Growing
Potting Soil Types Explained: Get Your Mix Right For Healthy Plant Growth
IN THIS GUIDE What Is Potting Soil? What Are Its Benefits? How To Use Potting Soil What Plants Is Potting Soil Good For? What Are Its Disadvantages? Disposing Of Old Potting Soil Common Reader Questions References Potting soil is the general name given to growing media that is used in pots and containers. Some people will simply refer to potting soil as compost. But this can get a little confusing, since it is not the same as an organic kitchen waste and garden waste compost you would make at home. What Is Potting Soil? The difference is that while a potting soil contains composted materials, it has been especially formulated to provide optimal conditions for plant growth. Often, potting soil will contain a blend of different ingredients. Potting soil can also be a term that is used to refer to a specific type of growing media which is specifically formulated – not just to provide good condition for a wide range of plants – but tailored specifically to cater to the needs of those plants which are in pots or containers. There are a number of different potting soil types available commercially, including: Peat-based options. Peat-free alternatives for the more environmentally minded. Loam-Based or Soil based potting soils. Organic potting mixes for those who really want to do the right thing for people and planet. Ericaceous mixes specifically for acid-loving plants. Mixes specifically for starting seeds. Some commercial potting soils are fairly simple in their composition, while others are more complex and contain other non-organic ingredients.1 It is important to understand that there is a lot of variation – not only in constituent ingredients but also in quality – when it comes to potting soil or potting mix that is commercially available. The term potting soil was first used in print in an 1861 issue of the ‘American Agriculturist’. But this term is also rather misleading, because the potting media is not actually soil at all. Most potting soils are actually soil-free, and those that are loam or soil-based only contain a proportion of soil, which is sterilized and only shares some, not all, characteristics with the soil in your garden. Whether you are potting on indoors sown seeds, or creating a container garden – choosing the right potting soil is key. But it is important to note that environmentally speaking, it is often best to make your own potting soil to fill the pots and containers in your garden. What Are Its Benefits? The benefits of using a potting mix (either commercial or home-made) for your pots and containers is that, if you make the right choices, you can provide optimal conditions for your plants. A good potting soil or potting mix can: Maintain good structure and oxygenation. Manage water availability – with the right balance of moisture retention and drainage for the specific plants you are growing. Provide nutrients for plants in the right quantities over the specific period of time. Different potting mixes will deliver nutrients to your plants for different lengths of time. Some will be depleted of nutrients much more quickly than others. It is important to understand that when growing plants in containers, you will usually have to provide further nutrients to your plants with liquid feeds and other supplements over time. And in certain cases, the potting soil should be replaced entirely with new, nutrient-rich material after a certain length of time. How To Use Potting Soil The first thing to remember is that choosing potting soil or container growing media should be a careful and thoughtful process. “Healthy soil is Absolutely crucial to the growth and health of our plants and trees,” shares Harry Hoblyn, the Head Gardener at Charleston Gardens. Different potting soils have different strengths and weaknesses, and can cater to different needs of different plants. Choosing one should always begin with an understanding of the needs and preferences of the specific plants that you will be growing in terms of moisture, water, soil structure, fertility and pH level. As an organic, sustainable gardener, you should also think about the environmental impacts of the choices you make. This might include avoiding the use of peat-based composts, perhaps also avoiding coir or other materials that have had to travel a long way (resulting in carbon emissions). “I have been growing my houseplants in peat-free mixes since 2017,” shares Jane Perrone, Houseplant Expert. “I use peat-free multipurpose compost with added John Innes called Silvergrow as my base for everything, adding additional materials from there as needed.” You might also consider creating your own potting mixes from locally available ingredients, to avoid purchasing materials for your garden in plastic packaging. “I mix and match the different components according to what I’m doing. That can be a pain, as storing it can be quite bulky, but you can buy readymade mixes too. “Some houseplant shops even have potting mix bars, where you can buy small mixes of things, which is really useful.” Once you have chosen a potting soil, you will, of course, use it to fill plant pots and containers prior to planting (or sowing) into them. Unlike an all-purpose medium, or all-purpose compost, potting soil is specifically used to grow plants in pots or other containers, and not typically used to amend or mulch the soil in a garden. What Plants Is Potting Soil Good For? The plants a particular potting soil is good for will depend on what its ingredients are and its exact composition. A general-purpose potting soil that you purchase (or make yourself) will usually be suitable for a wide range of houseplants, vegetables, herbs, flowers and other plants grown in containers. Some, however, will not be as good for seeds or seedlings. And as mentioned above, some are specifically formulated to meet the needs of acid-loving plants. This is why it is always so important to read the ingredients and information on a pack when you are purchasing a growing medium. And you must have at least a basic understanding of plant needs if you plan on formulating your own. What Are Its Disadvantages? The pros and cons of a potting soil depend very much on its ingredients and composition. As mentioned above, potting soils can vary significantly both in their make-up and their quality. Typically, if you are choosing a commercial brand, you will get what you pay for. Cheaper potting soil does not always represent good value for money, and if you choose a cheap and inferior type then plant health may suffer and you just won’t get the results you hope for. Making your own potting soil without carefully considering the needs of the plants you wish to grow can also lead to disappointments if you do not get it right. But one thing to say for making your own is that you won’t have wasted as much money if things do not go according to plan. And, of course, will also have avoided the environmental harm that many commercial brands can bring. All but organic and sustainable potting soils will cause some damage to our environment. So you need to ask yourself whether the true cost of these materials is worthwhile. Disposing Of Old Potting Soil One important thing to understand is that the nutrients in potting soil will be depleted over time, and must be replenished. It is also important to understand that diseases can build up if you use the same potting soil without thought year after year. That said, refreshing the potting soil in containers does not necessarily mean that you have to throw the old potting soil away. If the potting soil harboured a plant that succumbed to disease, then you should dispose of it carefully, to make sure that the problem does not spread. Make sure that you do not allow the contaminated material anywhere near your garden growing areas or composting system. However, where no problem has become evident, you can often recycle the potting soil. To do so: Carefully remove all plant matter (including root systems) from the potting soil. Dead plants that have not been infected with pests or disease can be added to your composting system. Remove debris from the medium by hand, or with a garden sieve. Put the potting soil on a tray and heat it in your oven for half an hour – make sure you do not do this at too high a temperature. This should kill off any pathogens or harmful organisms left within it. Allow the soil to cool, and leave it in a sealed container, out of the elements for storage. This process should make most potting soil safe for reuse. But it is important to remember that much of the nutritional content will have been depleted, and microbial life will have to be restored to allow these nutrients to be released and for plants to grow well. To make sure that the potting soil is able to successfully support plant life in future, you will need to supplement and amend it. We need the soil to contain microbes, which will continue to break down organic matter and release nutrients. We need to add more organic matter – e.g. kelp meal, alfalfa meal, to improve the structure and fertility of the mix. And can also add other things, like molasses, for example, to boost microbial life. Replenishing old commercial potting soil is not always easy for beginners. But as long as you understand about adding back organic matter and microbes, you can begin to learn how to build a healthy soil mix. If you have made your own simple potting soil with homemade compost, leaf mold and loamy soil then you will find it somewhat easier to make new mixes, since you can add more of these ingredients from your garden over time, as well as using liquid organic plant feeds to give plants a boost. If you have used an organic potting mix, you can also spread spent potting soil that has not been contaminated with diseases as a mulch along with additional organic matter around mature trees and shrubs in your garden. “As I only use peat-free potting compost that is derived from compost wood chips, I use it to mulch my borders when replenishing or emptying old pots and containers,” shares Horticultural Consultant Colin Skelly. “If I’m emptying a large container I use it to mulch around a tree or a hedge. This means it gets used twice and feeds the soil as well as the plants originally grown in it.” Common Reader Questions What Is The Difference Between Compost And Potting Soil? While the word ‘compost’ is sometimes used to refer to potting soils, they are really somewhat different things. Compost is made up of decomposed or partially decomposed organic material. While potting soil contains a proportion of decomposed materials, but usually has other materials mixed in. Many potting soils, for example, will contain mineral constituents like sand, for example. And may contain perlite, vermiculite, and perhaps additional synthetic or organic fertilizers. A homemade compost will be decomposed materials – usually a mix of carbon-rich brown materials and nitrogen-rich green materials. Its nutrient profile and characteristics can vary quite a lot depending on exactly what went into it and how exactly it was made. A potting mix, unlike a compost, is exclusively used in pots and containers. It is less beneficial when added to garden beds or borders. Compost can be used as an ingredient in filling pots and containers, but should usually only be used in conjunction with other materials. Compost can be an ingredient, for example, in homemade soil-based potting media, or homemade soil-less growing media. Typically, however, it should be mixed with other ingredients in order to create a more stable medium, with good water and aeration properties. For example, many plants can be happy in a general-purpose mix of 1/3 compost, 1/3 leaf mould, and 1/3 loam/loamy topsoil from a garden. You can also mix homemade compost with other ingredients like composted bark, coir etc. to make a soilless mix.3 Can You Mix Compost With Potting Soil? While you can make your own potting soil or potting mix from scratch, you need to be careful about mixing your own homemade compost with a commercial potting soil mix. Remember that commercial potting soil has been specifically formulated to provide for the needs of your plants. And a good example will be well balanced, with good moisture retention/ drainage and aeration. Make any changes to this container growing medium and you may risk disrupting this balance. That said, you can potentially eke out expensive potting soil by adding a small proportion of your own homemade compost to the mix – as long as the compost does not account for more than around a third of the overall volume of the mix. This should help to avoid compaction or drainage issues while providing nutrients that plants need to grow strong. This could be one way to improve cheaper and less ideal potting soils that have been purchased. How Long Does Potting Soil Last In The Bag? Potting soil will last almost indefinitely in an un-breached bag. However, as soon as a bag is opened to the elements, and gets wet, or is in contact with the soil, it will begin to leach nutrients and will become depleted over time. The organic material will continue to break down. The material will usually have depleted to the point where it is no longer ideal for plant growth in a matter of months. How Can You Remove Algae From Potting Soil? Algae on potting soil around seedlings or plants is often a sign that you are overwatering. Algae likes damp and humid to wet conditions. Avoid watering too much and make sure there are no drainage problems. In some cases, it may be better to water from below rather than from above. Make sure there is good airflow around your containers. Algae may also develop more readily where light levels are lower. Make sure your plants are in a bright and sunny area, or consider using LED grow lights if growing indoors early in the year. This problem is more common on peat-based media, since peat is very moisture retentive and provides the ideal conditions for algae to form. If you see this problem a lot, consider switching to peat-free media. This problem is also more likely to occur if you use garden soil rather than a soil-less potting mix. Garden soil can harbour spores (as well as fungi which can cause problems like damping off). Consider sterilizing soil before use, or switching to a soil-less recipe. Make sure containers are cleaned and sterilized before use to reduce the likelihood of this problem occurring. Once you take care of the environmental conditions and make sure these are right, you can often simply scrape the algae off the surface of the soil. In certain cases, it might be a good idea to add an organic mulch or soil cover (like sand, pebbles or grit) in the tops of your containers. With mature plants, you can repot if there is a major problem with competition from algae. But algae is usually only a serious issue when it comes to competition for seedlings and very young plants. Can I Use Garden Soil In My Pots? Yes, in a pinch, you can use a healthy garden soil in pots or containers for mature plants. However, this will not necessarily be the best choice, and won’t provide optimum results. Garden soil is best not used on its own, however, especially for seed starting. It can contain microorganisms that cause plant diseases, and may harbour pests. Another thing to note is that garden soil tends to be heavier and denser than potting soil. It is common, when using garden soil in pots and containers, to encounter issues with drainage and aeration. References 1. Smith, T., & Cox, D. (2015, August). Bagged Potting Mixes and Garden Soils for Home Gardeners. Center for Agriculture, Food, and the Environment. Retrieved March 23, 2023, from https://ag.umass.edu/home-lawn-garden/fact-sheets/bagged-potting-mixes-garden-soils-for-home-gardeners 3. Potting Media and Plant Propagation. (2012, August 28). PennState Extension. Retrieved March 23, 2023, from https://extension.psu.edu/potting-media-and-plant-propagation
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Why Peat-Based Compost Is Not An Environmentally Friendly Choice (Banned In 2021)
IN THIS GUIDE What Is Peat-Based Compost? Why Has Peat Traditionally Been Used? Costs Using Peat-Based Compost What Plants Is Peat-Based Compost Good For? Why Should Gardeners Use Less Peat-Based Compost? References Peat has traditionally been used by many horticultural experts and home growers to provide optimum conditions for their plants in pots, and to amend the soil in their gardens. However, in recent years, there has been a shift away from peat for environmental reasons. Many compost or potting mix manufacturers have moved away from peat altogether, or reduced the amount of peat included in their recipe. Sustainable, eco-friendly gardeners have tried to move away from these options to ones that are peat-free, and have less impact on the environment. What Is Peat-Based Compost? Peat based compost, as the name suggests, is a potting media or mix which includes a certain proportion of peat in its composition. Why Has Peat Traditionally Been Used? Peat has traditionally been used in growing media and soil amending composts because it is excellent for growing plants. Peat retains plenty of water and provides nutrients, while also providing a good texture that helps in maintaining aeration and avoiding compaction. Trying to recreate the qualities of peat with other materials has, historically, posed something of a challenge. But research and development of new commercial products means that there are now alternatives, which provide the same benefits as peat, without posing the same environmental threat. The horticultural industry in the UK is still heavily dependent on peat as a resource – but things are beginning to change, with the proliferation of higher quality peat-free options. Now, there are many peat-free alternatives that are just as good as peat-based options. In 2021, new legislation has banned the sale of peat to gardeners in the UK by 2024, with plans to help restore the UK’s peatland bogs.1 Costs One benefit of peat-based composts that does remain is that they are usually cheaper than peat-free alternatives. This means that they can be particularly tempting for those gardening on a budget. One thing to remember, however, is that you can also keep down costs by making your own growing media. This can also be achieved by using other materials to fill raised beds (no dig gardening lasagna beds) so only a smaller amount of compost is required to top new growing areas. Using Peat-Based Compost A peat-based compost, depending on its composition, can be used to grow a huge range of different plants. There are peat-based composts that can be used for starting seeds, growing plants in pots, and for spreading around plants to build and improve the soil in your growing areas. As mentioned above, peat is not a sustainable or eco-friendly choice. We’ll explain why in a little more detail below. Organic gardeners should always try to avoid using peat-based compost whenever possible, as Horticulturist Hannah Reid explains:2 “Avoid using peat products – only buy peat-free. Peatlands store huge amounts of carbon and harvesting it for compost is an environmental disaster. “It’s both horrendous for the biodiversity of that specific area and on a global climate scale. “Making your own fertilisers using common plants found in the garden like nettles and comfrey is a great substitute.” “Peat is an almost inert substance and has little if any fertilising benefit,” adds Dan Ori, a Horticultural Consultant. “It is what’s mixed with peat in products like multi-purpose composts that feed plants. The reason it is used in planting mixes (compost) or added to soil is that it has a high water-retentive ability over time. “The quality of peat-free multi-purpose composts has improved dramatically in the last few years, but you do have to adjust to a new watering approach, as peat-free composts will use more water than peat-based without adding additional materials.” Where it is preferable to use peat, and a good peat-free option cannot provide the same results (which is increasingly rare) gardeners should try to choose a lower peat option. Another potential option is to choose a compost that has peat sourced more sustainably – dredged from rivers and by dams where it has been naturally washed by rain, rather than choosing peat that has been dug up from its natural ecosystem. What Plants Is Peat-Based Compost Good For? There is no denying that peat-based compost is great for growing a wide range of plants. There are peat-based media that can be used for growing most plants from seed to maturity. (But also usually peat-free composts that can do just as good a job.) When starting seeds, multi-purpose composts can sometimes be used. But a specialist seed starting mix might yield better results. For ericaceous plants, a specialist acidic mix should be used. Why Should Gardeners Use Less Peat-Based Compost? The main disadvantage of peat-based composts is the harm they do environmentally speaking. Peat comes from lowland peat bogs. When we use it on a large scale in the horticultural industry, we are damaging these precious wetland environments.3 The problem is that although peat is a natural resource – we are using it up far faster than it can be replenished. And we need those peat ecosystems to remain for a number of reasons. Firstly, and importantly, peat bogs are a crucial carbon sink. Peat wetlands are the most important ecosystems for carbon sequestration on our planet.4 When peat is removed and peat ecosystems are degraded or destroyed, these ecosystems can no longer play their role in maintaining the world’s carbon cycle. We need to sequester more carbon, and lock it up in peat bogs and other carbon sinks in order to tackle the massive climate crisis we face.5 Wetlands are also very important in the water cycle. When we destroy peat bogs, we risk disrupting the flows of water through our environment. It is estimated that around 10% of the Earth’s freshwater is contained in peatlands.6 What is more, when peat ecosystems are degraded, water can also pass across a landscape more quickly. When we take peat away or disrupt natural systems, this can cause major flooding issues for communities at lower elevations.7 And it is not just people affected by peat removal. Many species of flora and fauna also rely on precious peat habitats. Wetlands are the most biodiverse of all nature’s ecosystems. When we disrupt and disturb them, we are contributing to habitat loss and biodiversity loss.8 These are just some of the main reasons why we should be leaving peat in the ground, not stealing it to use in our gardens. References 1. Carrington, D. (2021, May 18). Sales of peat compost to gardeners to be banned from 2024. The Guardian. Retrieved March 21, 2023, from https://www.theguardian.com/environment/2021/may/18/sales-of-peat-compost-to-gardeners-to-be-banned-from-2024 2. Peat belongs in bogs, not bags. (n.d.). The Wildlife Trusts. Retrieved March 21, 2023, from https://www.wildlifetrusts.org/ban-sale-peat 3. Peatlands and climate change. (2017, November). IUCN. Retrieved March 21, 2023, from https://www.iucn.org/resources/issues-brief/peatlands-and-climate-change 4. Why is peat so important? | Climate change. (n.d.). National Trust. Retrieved March 21, 2023, from https://www.nationaltrust.org.uk/our-cause/nature-climate/climate-change-sustainability/preserving-our-peatland 5. What is Carbon Sequestration and How Does it Work? (2019, September 20). Clarity and Leadership for Environmental Awareness and Research at UC Davis. Retrieved March 21, 2023, from https://clear.ucdavis.edu/explainers/what-carbon-sequestration 6. Trenbirth, H., & Dutton, A. (2019, July 22). UK natural capital: peatlands. Office for National Statistics. Retrieved March 21, 2023, from https://www.ons.gov.uk/economy/environmentalaccounts/bulletins/uknaturalcapitalforpeatlands/naturalcapitalaccounts 7. Shuttleworth, E. (2019, July 1). Peat restoration and natural flood management. IUCN Peatland Programme. Retrieved March 21, 2023, from https://www.iucn-uk-peatlandprogramme.org/news/peat-restoration-and-natural-flood-management 8. High Biodiversity. (n.d.). The Wetlands Initiative. Retrieved March 21, 2023, from https://www.wetlands-initiative.org/high-biodiversity
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Peat-Free Compost: You've Probably Heard Of It, But What Does It Really Mean?
IN THIS GUIDE What Is Peat-Free Compost? Sourcing Peat-Free Compost What Is It Made Of? What Are Its Benefits? What Do You Use Peat Free Compost For? How To Make Peat-Free Compost References Peat is a natural accumulation of partially decayed vegetation or organic matter. It is found in areas of peatland, bogs, moors and mires. What Is Peat-Free Compost? Peat free compost, as the name suggests, is any compost that does not contain peat. Peat has traditionally been used for creating potting composts because it has a range of benefits for growing plants. However, those who are environmentally conscious have recognised that digging up precious peat ecosystems to grow our plants is not a sustainable or eco-friendly choice.1 “There are many vital reasons for peat to be left in the ground,” shares Garden Writer Nic Wilson. “Healthy peat bogs support unique ecosystems, which include rare plants like the great sundew, and provide breeding sites for birds such as golden plover. “A peat bog also stores vast amounts of CO2, but stored carbon is released back into the atmosphere when peat is extracted, contributing to climate breakdown.” Consumers and compost manufacturers, therefore, are increasingly turning to alternative options – these peat-free composts were historically considered to be inferior to peat-based products for potting mixes. But research and development have now generated a range of products that can be as good as, or even superior to peat-based options. “We’ve been peat-free for 18 months across our whole nursery,” shares Rosy Hardy, the Owner of Hardy’s Cottage Garden Plants. “We were struggling to grow completely peat-free in our propagating area and we are still testing some substitutes, but we are not going back! “It’s good to be peat-free to help the planet, but it is hard as a commercial grower.” Sourcing Peat-Free Compost Gardeners can either make their own peat-free composts and potting mixes (see below) or purchase a product that states that it is peat-free on the label. Either way, watering and feeding requirements will usually be somewhat different for peat-free growing media than for peat-based options. One important thing to note about peat-free composts is that they can vary significantly in their ingredients and efficacy. Some are much better than others. Typically, price is indicative of how good a peat-free compost will be. The results of using a cheaper peat-free compost option will usually be more variable, and if you pay a little more, you will tend to see better results. Do not be tricked by terms on a label such as ‘organic’ or ‘eco friendly’ – such wording does not always guarantee that a compost or potting mix is peat-free. What Is It Made Of? Peat free composts and potting mixes can be made using a range of different ingredients, to a range of different recipes. Most peat-free options contain one or more of the following: Woody materials (bark, woodfibre, sawdust, etc..) Coconut husk (coir) Municipal green waste (usually no more than 30% of the finished product). Bracken Straw waste Waste sheep’s wool. A homemade growing medium usually comprises: Homemade compost (made with brown carbon-rich and green nitrogen-rich materials). Leaf mold Loam or sand (inorganic soil elements) What Are Its Benefits? A peat-free growing medium is far better for our planet. Using peat simply isn’t an option for anyone who wants to garden in a sustainable and eco-friendly way. Peat comes primarily from lowland raised bogs, which is an increasingly rare habitat type in the UK and across Europe.2 Peat bogs are important wetlands, which play a vital role in the water cycle, flood mitigation, and in drinking water provision and filtration.3 In the UK, more than 28 million people use drinking water from water sources that rely on peatlands.4 And globally, peatlands provide nearly 4% of all potable water stored in reservoirs.5 The distinctive environmental conditions of peat wetlands mean that they provide a crucial habitat for a wide range of flora and fauna. Preserving wetlands is crucial for preserving biodiversity and halting biodiversity losses. Wetlands are the most biologically diverse of all ecosystems, and it is vital that we protect these precious ecosystems. What is more, protecting peatlands is also crucial for carbon sequestration. Peatland ecosystems store more CO2 than all other vegetation types, including the world’s forests.6 Peat covers just 3% of the world’s land area but stores one-third of the Earth’s soil carbon.7 When we dig up peat for use in horticulture, we are hastening the destruction of these precious ecosystems and contributing to the climate crisis. The problem is that while peat is naturally replenished, it only grows very slowly (around 1mm per year). We are using it up far faster than it can naturally be replaced. Peat free growing media can be a far more sustainable and eco-friendly choice. Though it is important to look into exactly what goes into a peat-free compost, and where it comes from. When choosing peat free compost, we need to look at issues such as water retention, water distribution and nutrient provision. We need to balance our own needs and the needs of our plants with the needs of the planet and humanity as a whole to make the right compost choices for our gardens. What Do You Use Peat Free Compost For? Peat free composts vary considerably. Some are considered to be all-purpose composts, which can be used for a wide range of different plants through all stages of their growth. Some are specifically suited to seed starting, or for growing in containers. Others are specifically suited to ericaceous (acid-loving) plants. Make sure you pay attention to what exactly is in a peat-free compost, and read about the plants to which it is suited. Wood-based mixes tend to be suitable for most plants, as they have excellent drainage properties and low pH. Coir retains water well, and maintains good aeration, but does not hold nutrients well. Green waste, where this is used, has high levels of nutrients. But has high pH and may not always be the best option for seed starting and potting mixes. Bracken is high in potash Sheep’s wool provides slow-release nitrogen and is good for water retention. Make sure that you choose (or create) a potting mix suited to the plants you wish to grow. How To Make Peat-Free Compost It is perfectly possible to make your own peat-free compost/potting mix. There are a number of different recipes to consider, which combine compost made at home with organic matter with leaf mould, and soil ingredients like loam/sand. If you do decide to make your own then of course the results can be variable. One issue is that if you use a soil component, weeds and fungal pathogens can creep in. “Although the risk of weeds and pathogens tips the balance away from using home-made compost mixes”, says Horticulturist Colin Skelly, “the RHS recommends it as the best, lowest carbon option for potting on plants – although getting the technique right might take a bit of trial and error.” Personally, I have had few issues with using a mix of 1/3 compost (including well-rotted chicken manure and bedding as well as kitchen scraps, and shredded woody material from the garden), 1/3 leaf mould and 1/3 loamy soil to start my seeds. If you have issues with damping off when sowing seeds into this mix, you can sterilize the loam/soil using your oven. PH, moisture retention and available nutrients will be variable. But good composting practices can help you to establish a successful system and make a potting mix that works for a wide range of edible produce and other plants. “People have to remember that peat-free compost holds water more than they realise,” adds Rosy. “It dries out on the top, but can still be damp underneath, so it’s important to do the finger test and check that the soil is actually dry before watering.” You can also choose a soil-less recipe, and use woody materials or coir to create the right mix. Though coir is a waste product, however, it is worth noting that it may not be the most eco-friendly choice either, since it has to travel a long way to reach us. References 1. For Peat’s Sake. (2022, November 16). Garden Organic. Retrieved March 21, 2023, from https://www.gardenorganic.org.uk/get-involved/campaigns/for-peats-sake 2. Raised bog. (n.d.). The Wildlife Trusts. Retrieved March 21, 2023, from https://www.wildlifetrusts.org/habitats/wetlands/raised-bog 3. Anderson, R. (2022, February 9). Peatland ecosystem services. Forest Research. Retrieved March 21, 2023, from https://www.forestresearch.gov.uk/research/peatland-ecosystem-services/ 4. Harrison, A. (2018, May 15). Peatland contributions to UK water security. University of Leeds. Retrieved March 21, 2023, from https://www.leeds.ac.uk/news/article/4232/peatland_contributions_to_uk_water_security 5. Xu, J., Morris, P., Liu, J., & Holden, J. (2018). Hotspots of peatland-derived potable water use identified by global analysis. University of Leeds. Retrieved March 21, 2023, from https://eprints.whiterose.ac.uk/129766/6/Hotspots%20of%20peatland-derived%20potable%20water%20AAM.pdf 6. Peatlands and climate change. (n.d.). IUCN. Retrieved March 21, 2023, from https://www.iucn.org/resources/issues-brief/peatlands-and-climate-change 7. Huang, Y., & Wang, Y. (2021, June 22). Peatlands worldwide are drying out, threatening to release 860 million tonnes of carbon dioxide every year. World Economic Forum. Retrieved March 21, 2023, from https://www.weforum.org/agenda/2021/06/peatlands-worldwide-emissions-carbon-environment-climate-change/
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Organic Composts Are Made Without Synthetic Chemicals - How You Can Make Your Own
IN THIS GUIDE What Is Organic Compost? What Is It Made Of? How To Make Organic Compost Organic Compost Vs Potting Soil Where Can I Buy Truly Organic Compost? References The term ‘organic’ can be a confusing one. The term is sometimes used to describe anything of, relating to or derived from natural living things. This is the definition we use when we talk, for example, about adding organic matter to the soil in our gardens. What Is Organic Compost? Organic composts are any composts (or potting mixes) that do not contain any synthetic fertilisers, and which contain ingredients grown organically. And they may also be (though are not necessarily) free from peat, since though peat is a natural material, extracting it for garden use is hugely damaging to the environment.1 However, when it comes to buying compost, we are using the term ‘organic’ in a narrower sense. An organic product is a product that is grown/made without the use of man-made fertilisers, pesticides, herbicides or other harmful chemicals. Holistic organic production, however, also involves a systems approach that works towards environmentally, socially and economically responsible production. “When choosing a compost, sustainability should be at the forefront of any decision,” shares Master Horticulturist Peter Lickorish. “This may include how compost is packaged. Buying one larger bag will involve less plastic use than two small bags, though be careful when handling large bags of compost. “Some bags are recyclable through plastic collections, such as at garden centres. You could repurpose compost bags to line hanging baskets or for growing potatoes. “Buying a block of coir, which can be hydrated to a much larger size for use at home, saves on transport emissions. “Even though it is not grown locally, its lightweight nature means it can have a lower carbon footprint for transport than other materials. Remember to check that the coir is organic.” Of course, the easiest and cheapest way to get your hands on some organic compost is to make your own in your garden. Homemade compost is the most eco-friendly and sustainable choice of all.2 Since you make it yourself, you will know exactly what has gone into it, and will have ultimate control over the credentials (and quality) of the product. However, there may sometimes be times when you cannot make enough, or cannot do so quickly enough. In which case, buying organic compost is the next best choice, environmentally speaking. Buying organic compost that is free from harmful chemicals, and peat-free, is a far better choice than selecting other forms of compost, which will pose a threat to the environment. Though it is important to work out whether you want a true compost, or are actually looking for an organic potting mix, as these are two different things. What Is It Made Of? Organic compost can be made up of a range of different materials. If you are making your own organic compost then of course it will be made up of all the different ingredients that you added to your composting system. It will contain both brown (carbon-rich) and green (nitrogen-rich) materials. If you purchase an organic compost, it will usually be either a soil-improving compost comparable to a homemade compost, or a potting mix. Which one you will choose will depend on how exactly you wish to use it in your garden. Organic potting mix is usually a soil-free mix, which includes a proportion of composted waste, mixed in with a substrate of other peat-free materials. Organic composts or potting mixes can be purchased which have a range of different ingredients and formulations. Some, for example, are made from a mix of composted forest or garden cuttings – or organic green waste such as composted bark fines, coconut husk, bracken, wool etc. Of course, whichever ingredients go into the blend, these are organic in origin. Though organic composts do not contain the synthetic fertilisers that are added to some other composts on the market, the blends have been carefully worked out to ensure good fertility and good plant growth and so results are now comparable with other non-organic options on the market. How To Make Organic Compost There are a number of ways to make your own organic compost at home. You can compost in place in a no dig gardening system, or set up a simple cold composting heap or bin. You can also speed up decomposition by aerating the mix (with a compost tumbler, for example), by enlisting the help of special worms (and setting up a vermicomposting system), by increasing temperatures (and making a hot composting system) or by using bokashi systems (and fermenting scraps prior to composting). Of course, whichever composting method or methods you choose, it will only be organic (in the narrower sense) if you garden organically and none of the ingredients you add are contaminated with pesticides, synthetic fertilisers or other harmful substances. “When I make compost at home, I aim for around 60% finely chopped brown carbon material and 40% green material,” says Peter. “The mix may vary to control moisture, such as whether cardboard is used, which can soak up water, or twigs, which aid aeration.” If you want to create your own potting mix, you can do so by combining this sort of homemade organic compost with other ingredients. You can increase the density of your potting mix by combining homemade compost with loam or garden soil. The added weight may make tall pots more stable, but the potting mix may slump over time. Adding leaf mould or other ingredients can reduce density and create a more friable, aerated mix. Organic Compost Vs Potting Soil An organic compost is used to add fertility to growing areas and improve the soil. It is an essential ingredient in organic gardening. Organic compost can be used as the top layer for new no dig garden beds, and spread as mulch around your plants. An organic potting mix is formulated specifically for starting seeds, and growing on plants in pots. It is also a medium designed to promote healthy growth for plants grown in containers. Typically lower in nutrients, but with a better texture for water retention/ drainage and aeration, a potting mix will usually also require the addition of organic fertilisers throughout the growing season. “With the cost of compost, I always recycle my old pot compost by adding in a bit of organic matter grit and slow release fertiliser,” says Laura from The 3 Growbags. “However, this can lead to a problem with weeds, so I just put a surface layer of bought (so sterile) compost to finish off the new planting and stop the light from getting through to trigger the germination of the weeds.” Where Can I Buy Truly Organic Compost? Organic compost or organic potting soil is increasingly being offered as an option in garden centres and plant nurseries. However, you may find it easier to find organic options online. Here are a few great options: Dalefoot Composts (Certified Organic by the Soil Association) Fertile Fibre (Certified Organic by the Soil Association) Moorland Gold (Certified Organic by the Soil Association) One other recommended sustainable option, though not completely certified organic in origin is Melcourt Sylvagrow Sustainable Growing Medium (Endorsed by the RHS). References 1. Environmental experts call on retailers to end sale of climate-harming compost. (n.d.). Sustain. Retrieved March 21, 2023, from https://www.sustainweb.org/news/jun21-sustain-calls-for-ban-of-peat-free-compost/ 2. Cathey, A., & Ashrap, P. (2019, September 19). Trash to Treasure: The Incredible Benefits of Composting. The Regents of the University of Michigan. Retrieved March 21, 2023, from https://sph.umich.edu/pursuit/2019posts/benefits-of-composting.html
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These Are The Benefits Of Loam-Based Compost (And How You Can Make Your Own)
IN THIS GUIDE What Is Loam-Based Compost? What Is It Made Of? What Are Its Benefits? How To Make Loam-Based Compost What Plants Is Loam-Based Compost Good For? When To Avoid Using It References John Innes composts are popular here in the UK, and in other countries. What Is Loam-Based Compost? A loam-based compost is a compost that contains a certain proportion of loam soil. Most potting composts do not contain any soil at all. But there are some – most notably the John Innes composts, that do have some ‘soil’ in their composition. It is worth noting that the common John Innes loam-based composts contain soil ingredients that are not necessarily loam in their modern formulations. Loam is the name given to soils that are balanced mixtures of mineral components of different sizes: clay, sand and silt. They also have an organic matter component. These soils are the best soils for gardeners. They combine the best qualities of different soil types and are great for plant growth. The loam in loam-based composts is sterilised to get rid of weeds, pests and diseases. This means that the gardener should encounter fewer problems than they would with a non-sterilized soil-based growing medium. There are several different common John Innes composts, or potting media that are on the market today. These are: John Innes Seed Compost – for seeds and cuttings John Innes Potting Composts (Soil Mix and Fertiliser Base) – best for established plants and general use John Innes Compost No. 1 – for seedlings and cuttings John Innes Compost No. 2 – for transplanting young plants or plants that don’t thrive in rich soil like thyme John Innes Compost No. 3 – for established plants John Innes Ericaceous Compost – for acid-loving plants There are also peat-based and peat-free composts/ growing media with ‘added John Innes’. “I strongly suggest trying the peat-free mixes of John Innes,” says Horticulturist Dan Ori, “they perform well and manufacturers are not having to harvest from peat bogs to make them. “It will take a little adjustment to understand when to water, as it is different to compost containing peat; if you use a moisture meter to help you judge when to water, you will find it an easy transition.” Read on to learn what exactly goes into each of these different soil-based growing media mixes. What Is It Made Of? The various types of loam-based John Innes compost have different ingredients and contain materials in differing quantities. Here are some details to help you understand what is in John Innes loam-based composts, and how to make these products yourself following their recipes.1 John Innes Seed Compost is used for sowing seeds, and for cuttings, and seedlings can be grown on in it until they are ready for pricking out. It comprises: 2 parts loose bulk medium sterilized loam. 1 part peat or peat substitute. (Peat is often replaced with other materials and this is a more eco-friendly choice.) 1 part coarse horticultural sand. John Innes soil mix is: 7 parts sterilized loam. 3 parts peat or peat substitute. 2 parts loose sand. And John Innes fertiliser mix (also known as John Innes base) is: 2 parts by weight of hoof and horn meal. 2 parts by weight of superphosphate. 1 part by weight of sulphate of potash. John Innes Compost No.2 is used to grow many houseplants, and vegetable plants in containers. For each 2 gallon bucket of soil mix, add 56g of fertiliser mix, and 10g ground chalk. John Innes Compost No.3 has even more nutrients. It is used for established trees, shrubs and other mature plants, and mature indoors plants that will remain in their containers for a long time. This mix is also good for particularly ‘hungry’ plants like tomatoes, for example. Add 84g of fertiliser mix and 15g of ground chalk. What Are Its Benefits? Loam based composts can be beneficial because the loam helps to avoid fluctuations in water and nutrient content in the growing medium. Since the soil part of the media is very stable, this can be especially useful in situations where plants are placed for the long term. How To Make Loam-Based Compost It is important to note that you can make your own loam-based compost mixes at home. And you do not necessarily have to stick to, or remain close to, the formulations described above. One option if you have a good quality loam soil in your garden is simply to use some of that. You can also make a good loam by stacking turfs of grass upside down until it breaks down. As mentioned above, all commercial loam-based composts use sterilised loam. The sterilisation process is undertaken because soil or loam that has not been sterilised can contain weeds, pests and diseases. It is not especially easy to sterilise loam at home, but it is possible to do so in your oven. Personally, I use a mix of 1/3 loam (from the garden), 1/3 homemade compost (with well-rotted manure and bedding from our chickens) and 1/3 leaf mould (from autumn leaves) to make a mix that works well for mulching around vegetables and placing in containers. I do not bother with sterilisation and while there will be the odd weed here and there, and the odd problem, these are not too much of an issue in my organic garden. What Plants Is Loam-Based Compost Good For? A loam-based compost can be good for a wide range of different plants. The right loam-based formulation can be used at all stages of plant growth. But it is important to remember that there are certain plants that need a different formulation, that is more free draining or which contains a specific mix of nutrients. Loam based composts are generally excellent for the vegetable garden, and for mature plants that will remain in place for longer periods of time. They can be used for indoors or outdoors container gardens. And can often be the best choices when plants are not grown in contact with the natural soil. When To Avoid Using It Commercial composts of this type, either John Innes composts, or composts with ‘added John Innes’ should have been specially formulated to allow for good drainage, aeration, fertility and optimal plant health and plant growth. It is always important to note that as with other composts, the quality of these commercial composts can vary considerably. Some are much better than others. The texture of store-bought compost with loam will vary considerably depending on the exact composition of the loam and where the material came from. Those who are trying to avoid harmful practices and want to garden as sustainably as possible should aim to avoid choosing products that contain peat, non-sustainably sourced loam, and any non-organic fertilisers or other problematic ingredients. If possible, in order to make your gardening efforts as sustainable as possible, you should try to take a DIY approach, using materials sourced from your own home and garden, or as locally as possible. References 1. John Innes potting compost. (n.d.). Royal Horticultural Society. Retrieved March 20, 2023, from https://www.rhs.org.uk/soil-composts-mulches/john-innes-compost
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All (General) Purpose Compost - What Is It Made Of And When Should You Use It?
IN THIS GUIDE What Is All Purpose Compost? Considerations What Is It Made Of? What Are Its Benefits? How To Use General Purpose Compost What Plants Is All-Purpose Compost Good For? When To Avoid Using It Frequently Asked Questions References When people talk about a multi-purpose or ‘all-purpose’ compost, they are usually referring to commercial composts that you can use in your garden in a range of different ways. These commercial composts are specially formulated with a range of different ingredients. What Is All Purpose Compost? All-purpose compost is a multi-purpose compost that will suit a wide range of applications in your garden. They can provide nutrients, and the right growing environment for a wide range of plants, at all stages of their growth, right through from seed sowing to maturity. All-purpose composts can be used as mulch to enrich beds, borders and other growing areas. They can also be suitable for filling planters, containers and pots for houseplants and for an outdoors container garden. Considerations Since all-purpose composts are ostensibly formulated for use in a huge range of different ways, this means that they can often be a good choice for new gardeners. It is important to understand, however, that all-purpose composts vary significantly in quality. While these composts can often be cheaper than other more specific use composts, results can be variable. Even bags of compost from the same company have been found to vary significantly in quality. It is also important to recognise that all-purpose composts can vary in how eco-friendly and sustainable they are. Their credentials can vary quite considerably in this regard depending on what ingredients are mixed into them. What Is It Made Of? A general-purpose compost is made from biodegraded (or rather partially biodegraded) organic material. But which materials went into making the compost will depend on the formulation of the commercial compost you choose (or what you put into your composting system if you made it yourself). Many all-purpose compost brands contain peat. But there are other peat-free alternatives to consider, and you should do so. Peat free multi-purpose composts can be wood-based, wool-based, or coir based, for example. Commercial brands of all-purpose compost often also include other ingredients intended to promote healthy and strong root formation and plant growth. For example, all purpose compost often includes materials designed to help in aeration, such as vermiculite or perlite. Vermiculite is a light, spongy material which is a naturally occurring mineral resembling mica, and holds more water and nutrients as well as aerating the mix.1 Perlite is expanded volcanic glass and gives a compost that is more free-draining. Though these can be helpful for gardeners, it is worth noting that neither is a particularly eco-friendly option. Some all-purpose or multi-purpose compost brands will also incorporate some controlled-release synthetic fertiliser capsules that will slowly release nutrients over a matter of weeks or months. If you wish to garden organically then these are, of course, options that should be avoided. What Are Its Benefits? A good quality all-purpose compost is usually the cheapest sort of compost that you can get. Short of creating your own compost at home, of course, this is the most affordable option. This also makes things easy for new gardeners, as they do not have to think too deeply about which compost they need for specific uses in their gardens or containers. How To Use General Purpose Compost As mentioned above, general-purpose compost can be used for a range of different garden applications. Also, the nutrient composition of different all-purpose composts can vary significantly. In general, a good all-purpose compost is great for: Topping new raised beds or growing areas (for example, those made with the no dig lasagna method) in your garden. Mulching existing beds, borders or growing areas to replenish fertility and protect and improve the soil. Filling containers for a range of indoors and outdoors grown plants (any that do not have more specific needs when it comes to their growing medium). What Plants Is All-Purpose Compost Good For? An all-purpose compost is good for placing as a mulch, or using as a growing medium for mature plants (some are also fine for seed sowing, seedlings and cuttings, though this depends on the particular brand and its formulation). It can be very useful in growing a wide range of plants, including many fruits and vegetables in a food-producing garden, shrubs, trees, bedding plants and herbaceous perennials. When To Avoid Using It Avoid using an all-purpose compost for plants that have more specific requirements when it comes to their growing medium. For example, some plants are ericaceous and require an acidic compost growing medium or mulch. Others require better drainage than a typical all-purpose compost provides. We recommend that you avoid purchasing all-purpose composts that contain peat, due to environmental concerns.2 We also suggest that you look into making your own, so you can significantly reduce the amount of multi-purpose compost you must buy in future. Frequently Asked Questions Can You Use All Purpose Compost For Acidic Loving Plants? Whether you bought it or made it yourself, the pH level of an all purpose compost can vary quite a lot. Usually, it is neutral to mildly acidic. It will have been formulated to be suitable for as wide a range of plants as possible. However, because it has been formulated to suit many plants, it will not be suitable for some – including plants that like acidic growing conditions. For plants that require acidic conditions like, for example, azaleas, many heathers, acers, blueberries, etc. you should use an ericaceous compost. This is an acidic compost that has been formulated to provide growing conditions with a lower (more acidic) pH. Ericaceous compost that you either buy or make yourself will be a better choice for growing these plants in containers, or for using as mulch around them. How Long Does All-Purpose Compost Last? How long all purpose compost will last before it is used depends to a large degree on how it is stored. If it is kept dry, and in a sealed container, then it should last indefinitely. On the other hand, if the container is breached, or the compost is on the soil or open to rainfall, the nutrients within it will slowly start to leach out and the materials will continue to break down. The compost will usually have depleted to the point where it is no longer ideal for plant growth within a few months. If you have used an all-purpose compost in containers, you should note that you’ll need to replenish the nutrients in it over the growing season to encourage plants to continue to grow strong. To give plants a boost, you can top-dress or mulch around the tops of the containers with organic matter/soil enriching materials. And you can use organic liquid plant feeds to give plants nutrients more quickly. With many plants, you should plan to replace the growing medium in the pots every 2-3 years. If you are mulching around plants in your garden, compost is great as a slow-release fertiliser and will also improve the soil. Micro-organisms will feed off organic matter in the compost that has not yet fully decomposed, and soil biota will help incorporate the compost and its nutrients into the soil below. You should plan on replenishing the growing areas with compost or other fertilisers/soil amendments at least once a year. Should You Use This Compost Type For Indoor Plants? All-purpose compost is fine for many houseplants. But certain groups of plants, like orchids, bromeliads, succulents and cacti will require more specific compost mixes and will not thrive in an all-purpose compost. Can I Use All-Purpose Compost For Seeds? Some general-purpose composts will be fine for seed sowing, seedlings and cuttings. Others, however, may not be the best choice for these stages of plant growth. What it comes down to is the texture of the compost, and how fine-grained it is. If it is relatively fine-grained, it will often be suitable for seed starting. Remember, seeds need water, oxygen and the right temperatures for germination, but they do not yet need to take in nutrients from the soil. This means that special seed composts are sometimes used, which tend to be low in added nutrients, yet have a texture that helps seeds and young seedlings. One benefit of using a more general compost (either an all-purpose compost you have bought which has a fine enough texture, or a compost/ potting mix you have made yourself at home) is that the seeds can be left to grow on in this medium. So ultimately they don’t necessarily have to be moved to different containers filled with a different growing medium for the next stage of their growth. Do Mice Eat Multi-Purpose Compost? Mice will not eat a potting mix or compost itself, unless it is a poor mix with non-decomposed organic material. However, they may enjoy the friable texture of the mix and use it to hide within, and as a place to store bits of found food. References 1. What Is Vermiculite? (n.d.). The Vermiculite Association. Retrieved March 28, 2023, from https://www.vermiculite.org/blog/horticulture/what-is-vermiculite 2. Sams, C. (2021, August 27). Gardeners should end their love affair with peat. The Guardian. Retrieved March 10, 2023, from https://www.theguardian.com/environment/green-living-blog/2012/apr/05/gardeners-peat-carbon
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Did You Know You Can Use Old Coffee Grounds In The Garden? Here's How To Compost Them
IN THIS GUIDE Why Coffee Grounds Should Be Composted Why They’re Useful in Compost Creation Composting With Coffee Grounds Methods for Composting Coffee Grounds 1) Typical Cold Composting (Heap Or Bin) 2) Vermicomposting 3) Bokashi Systems 4) Hot Composting 5) Composting In Place References Coffee grounds can be a very useful organic material, but composting them is only a good idea with certain caveats. In this article, we’ll look at the reasons why composting coffee grounds can be a good idea, but we’ll also take a look at why you have to be careful. We’ll explain the different methods for composting coffee grounds, and talk about how to avoid some common pitfalls. Why Coffee Grounds Should Be Composted It is important to understand that coffee grounds should ideally be composted before you use them in your garden in any other way. Caffeine Effects The first thing to consider is that un-composted coffee grounds contain caffeine – and caffeine can have an allelopathic effect.1 This means that this substance can limit or curtail the growth of plants, making it prohibitive to use in the garden.2 This substance originally developed in plants as a means to reduce surrounding competition. It gave the plants that contained it a competitive advantage. Caffeine does not have this effect on all plants, but it could, when used as a mulch, cause certain plants to be less strong and healthy. Scientists have also discovered that the caffeine present in coffee grounds can be sufficient to stop certain seeds from germinating effectively.3 So it would not be a good idea to spread it, for example, in a vegetable garden where you are about to plant some seeds. Compacting Issues Another reason that un-composted, unmixed coffee grounds are not a good idea as a mulch is that they compact very easily. The coffee grounds, when laid as a mulch, can form into a crust over the soil. It is a good idea to keep soil covered, either with a mulch or with living plants, but the soil covering should allow water and air to flow through. Coffee grounds compact and therefore can restrict air and water flow to the soil beneath. So when used incorrectly, this is another reason why coffee grounds in the garden could do more harm than good. You can sprinkle some coffee grounds around plants and cover them with a mulch of leaves, straw, leaf mould or garden compost. But turning the coffee grounds themselves into compost before using them as a mulch or soil amendment in your garden is usually a much better idea. Why They’re Useful in Compost Creation So far, we’ve focussed on the negative effects of using coffee grounds in the garden; you might be wondering why we should go to the effort of composting them. The fact of the matter is that coffee grounds, in spite of the limitations mentioned above, can be beneficial for your garden when used in the right way. Reducing Waste In organic gardening, we should always try to avoid waste whenever we can. We should do our best to recycle nutrients and complete nature’s cycles to grow our food and other plants. Composting coffee grounds is one of many ways that we can reduce waste and live in a more sustainable way.4 Increasing Garden Nutrients Creating compost is also very useful for the long term health of our gardens. When we compost coffee grounds along with other organic matter and kitchen waste, we reclaim the nutrients those materials contain. Coffee grounds are rich in nutrients essential to plant growth – especially nitrogen. The nutrients they contain can help create compost that will feed your plants.5 Nitrogen is important in a composting system. Often, the materials used in composting are categorised as either nitrogen-rich (green) or carbon-rich (brown) materials. Though brown in colour, coffee grounds are characterised as a ‘green’ material due to their relatively high nitrogen content. Adding nitrogen-rich materials like coffee grounds to a composting system helps the materials to break down more quickly. But be warned, though coffee grounds can be useful in composting, too many coffee grounds in composting can do more harm than good.6 Composting With Coffee Grounds The most important thing to understand is that coffee grounds should only be added to any composting system a little at a time. Avoid Adding Too Much Adding too many at one time without adding other materials can often have a detrimental effect. You need to keep the compost in balance, and add plenty of carbon-rich materials too. A composting system with too many nitrogen-rich materials and not enough carbon-rich materials can quickly become anaerobic.7 This means that the materials will decompose without oxygen – and that can mean that the compost will get slimy and begin to stink. Anti-Microbial Properties Another major problem is that coffee grounds can have anti-microbial properties. The goal in home composting is usually to create the right environment and conditions for aerobic decomposition (the breakdown of organic materials in the presence of oxygen). For decomposition to take place, we need oxygen, water, the right temperatures, and, crucially, a healthy population of micro-organisms. Composting relies on the presence of a range of fungi, bacteria and other life.8 Unfortunately, adding too many coffee grounds to a composting system can kill the beneficial microbes upon which the system depends. Effects On Earthworms Vermicomposting experts suggest that as coffee grounds break down in a composting system, they release organic compounds and chemicals that may harm or burn earthworms.9 In composting, we rely not only on micro-organisms but also on other soil life – worms included. The fact that coffee grounds may harm them is not good news for your garden. But it is also suggested that adding plenty of carbon-rich feedstock to the compost reduces this problem. Methods for Composting Coffee Grounds Which composting method you choose for disposing of coffee grounds will play a role in determining how beneficial it can be, and also on how much of this material can be added to the system at one time. Below, we’ll look at some common composting methods that could be effective ways to recycle and retain the nutrients that coffee grounds contain: 1) Typical Cold Composting (Heap Or Bin) The most common form of composting in a domestic setting is simply adding your ‘brown’ and ‘green’ materials to a heap, bin or other container. This type of composting is known as ‘cold composting’. The materials do heat up to a degree in these systems as they decompose, but they will not heat up as much as they do in a hot composting system (described below). 2) Vermicomposting Sometimes, special composting worms are deliberately added to a compost container. These composting worms eat through the organic material added and create ‘worm castings’ (worm poo). Worm castings are great for adding fertility and improving garden soil. Composting with worms is known as vermicomposting – it can be beneficial in speeding up the process of decomposition in cold composting systems. But coffee grounds should not be added to a vermicomposting system (at least not in any significant amount). A small quantity as a once-off will likely not do much harm as long as there is plenty of carbon-rich material (cardboard, dried leaves, etc..) in the system. But you should not make a habit of adding coffee grounds to a system of this kind due to its impact on the worms. If you plan to compost coffee grounds on a regular basis, it would be best to avoid a vermicomposting system. Instead, it will be better to use other means to speed up decomposition if you want to create compost more quickly. Investing in a compost tumbler (which will improve aeration) is one idea. Note that it is possible to add more coffee grounds to your vermicomposting system if you ferment your food waste in a bokashi system first. 3) Bokashi Systems Bokashi is not technically composting. Organic material is fermented rather than rotted – but it can be another interesting way to manage coffee grounds and avoid waste. A bokashi system also allows you to compost other ‘tricky’ compostable materials. Such as meat and dairy products, for example. Fermenting the coffee grounds first before adding them to a cold composting or vermicomposting system could be a good idea. Some people experiment with using coffee grounds in place of the bokashi ‘bran’ usually used in bokashi systems. So if you have access to large quantities of coffee grounds that you want to ‘recycle’ into soil amendment for your garden then this is something intriguing to look into further. 4) Hot Composting In a hot composting system, the goal is to achieve higher temperatures than in a cold composting system. The higher temperatures mean that the materials will break down more quickly. In hot composting, the temperature should be 60-68°C. Coffee grounds can be beneficial to add in reasonably low quantities to a hot composting system because, as a nitrogen-rich material, they can help keep up the temperatures inside the heap or bin. One of the negative impacts of composting coffee grounds is, as mentioned above, the effects on earthworms. In a hot composting system, you will generally aim for a different carbon to nitrogen ratio than you do in cold composting. As mentioned above, adding plenty of carbon can reduce this negative impact. So hot composting coffee grounds with plenty of carbon could be better for earthworms in your garden. You can hot compost coffee grounds along with other compostable materials in a heap or a container. A heap should not be too small (ideally, it should be no less than 4ft tall and 4ft wide so materials heat up enough inside). If you are using a container, it should be of a material that can absorb and retain heat. Yet should be ventilated so the mix does not become anaerobic. Hot composting can be more challenging than cold composting, but it will allow you to compost a wider range of materials – including small quantities of coffee grounds – more quickly. 5) Composting In Place We’ve already mentioned above that using coffee grounds as a mulch on their own is not a good idea, but there is one way to add them directly to your garden. That is, through composting in place. Unlike the other methods of composting mentioned above, this method does not involve creating a separate composting area in your home or garden. Rather, it involves layering organic materials in place on your growing areas or garden beds. Composting in place is sometimes referred to as ‘sheet mulching’. It can be used to create new growing areas or raised beds. As in a traditional composting system, this involves adding layers of ‘brown’ and ‘green’ materials. Since materials are added in layers, new beds made in this way, by composting in place, are sometimes referred to as ‘lasagna beds’. The materials in this type of growing area will break down in situ to slowly release nutrients for your plants. Coffee grounds can be added to the ‘green’ layers of lasagna beds or in sheet mulching in moderation as long as they are well-mixed with other materials. Care does need to be taken when composting with coffee grounds, as Master Horticulturist Dan Ori shares: “It does astound me how many people use coffee grounds on their garden thinking they are doing good when I have been trialling the use of spent coffee grounds as a weed growth suppressant. “Personally, I advise you not to use coffee grounds in the garden, and if you are going to add some to cold or hot composting, I would only add trace amounts. “I wish I could tell you a maximum trace amount to use in composting, but we just don’t have the studies to take an informed stab at a figure.” But get it right, and you can use the compost you create to add the nutrients they contain to your garden. References 1. Sugiyama, A., Sano, C. M., Yazaki, K., & Sano, H. (2016). Caffeine fostering of mycoparasitic fungi against phytopathogens. Plant Signaling & Behavior, 11(1), e1113362. https://doi.org/10.1080/15592324.2015.1113362 2. Research Progress on the use of Plant Allelopathy in Agriculture and the Physiological and Ecological Mechanisms of Allelopathy. (2015, November 17). Frontiers. Retrieved March 14, 2023, from https://www.frontiersin.org/articles/10.3389/fpls.2015.01020/full 3. Ransom, F. (1912). The Effects of Caffeine upon the Germination and Growth of Seeds. Biochemical Journal., 6(2), 151–155. https://doi.org/10.1042/bj0060151 4. Composting as a key to a sustainable future. (n.d.). Planet Forward. Retrieved March 14, 2023, from https://www.planetforward.org/idea/composting-as-a-key-to-a-sustainable-future 5. Coffee Grounds Perk up Compost Pile With Nitrogen. (2017, October 5). Oregon State University. Retrieved March 14, 2023, from https://today.oregonstate.edu/archives/2008/jul/coffee-grounds-perk-compost-pile-nitrogen 6. Wake up and use the coffee – grounds, that is! (n.d.). ANR Blogs. Retrieved March 14, 2023, from https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=12978 7. Hu, S. (n.d.). Composting 101. NRDC. Retrieved March 14, 2023, from https://www.nrdc.org/stories/composting-101 8. Chapter 1, The Decomposition Process. (n.d.). Texas A&M University. Retrieved March 14, 2023, from https://aggie-horticulture.tamu.edu/earthkind/landscape/dont-bag-it/chapter-1-the-decomposition-process/ 9. Vermicomposting 101: Do Worms like Coffee Grounds? (2023, February 15). Uncle Jim’s Worm Farm. Retrieved March 14, 2023, from https://unclejimswormfarm.com/using-coffee-grounds-for-vermicomposting/
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5 Ingenious DIY Potting Soil Recipes With Tips From Sarah Gerrard-Jones
IN THIS GUIDE DIY Potting Soil Recipes For Growing Key Ingredients For Potting Soil Go Potty For DIY Potting Soil References Whether it’s growing your own fruit and vegetables, making your own compost, or upcycling old household items to use as containers for growing – many gardeners nowadays are trying to become more self-sufficient, no longer wanting to rely on shop-bought products. As peat-based products are not sustainable and alternatives offered can be variable in terms of nutrient provision and even at times include herbicides in error, needless to say, a lot of gardeners are also opting to make their own potting mix. It’s not as difficult as you would imagine, and can be a real money saver. There are many more benefits that come with making your own potting soil including the fact that you know exactly what nutrients are in your soil, and you can tailor it perfectly to the plants you are working with. It also means you can be sure that you aren’t accidentally exposing your plants to any nasty herbicides or pesticides. So, if you’re eager to start making your own DIY potting soil, then this article will tell you everything you need to know to get started. Firstly, your DIY potting soil should be consistent, lightweight, and easy to handle. You can tailor your potting soil to the precise needs of your plants by creating your own unique blends – If you are starting seeds or root cuttings, you will want to create a lighter, finer-textured mix. For shrubs and trees, you will require a mix that consists of a high level of coarse sand or bark. If you are growing succulents or cacti, then you will want to opt for a sandy and gravelly texture. When it comes to growing containers of annuals, perennials, vegetables or tropicals, then a general, all-purpose potting mix is ideal. DIY Potting Soil Recipes For Growing Now that you have an understanding of what potting soil is and have familiarised yourself with the ingredients needed to create it, it’s time to start mixing! We have picked out the best DIY recipes to help you make the perfect potting soils for your needs. Making your own potting soil isn’t difficult and, as you come to understand it better, you will be able to manufacture whatever type you require for your pot plant growing needs. “You need to think about what kind of plant you’re growing, whether it’s a houseplant or a succulent, and where it is native to,” shares Houseplant Expert Jane Perrone. “If it’s coming from a free-draining place, you’ll need to add lots of drainage material. There are so many things you can use for this, like perlite, grit and horticultural sand, as mentioned above.” You can use a wheelbarrow to mix your blends, or if you want to make blends in bulk, you could also use a compost tumbler or even a cement mixer. 1) For Annuals, Perennials, Fruit & Veg 6 parts coir 4 and ½ parts perlite 6 parts garden compost or composted bark 300g of organic fertiliser per 75 litres of potting mix 2) For Seed Starting 3 parts coir 1 part perlite 1 part vermiculite 2 parts sharp sand 3) For Shrubs & Trees 3 parts coir 3 parts garden compost 2 and ½ parts sharp sand 3 parts perlite 2 and ½ parts composted bark (pine bark can be substituted for shrubs and trees that require additional acidity) 200g organic fertiliser per 64 litres of potting mix 4) For Pot Plants 2 parts coir 1 and ½ parts perlite 2 parts sharp sand 28g of organic fertiliser per 25 litres of potting mix 5) For Cacti Or Succulents 3 parts coir 1 part perlite 1 part vermiculite Key Ingredients For Potting Soil Before you start creating your own DIY potting soil, it’s essential to familiarise yourself with the key ingredients that you will be working with and what part they play. 1) Sphagnum Peat Moss Sphagnum peat moss is a coarse, stable material that takes a long time to break down. Lightweight and inexpensive, it’s used to bulk up your mixture and also holds water well. You will want to take care not to add too much Sphagnum peat moss as this can slow or even stop drainage. It is also harmful to the environment, so we would recommend seeking alternative materials where possible. It also does not contain a lot of nutrients and has an acidic pH; you can add limestone to balance this. “As peat-based compost will no longer be sold in the UK from 2024, I’d recommend that you start to use alternatives now to become accustomed to the different watering and feeding regimes that are needed for peat-free compost mixes,” suggests Roy. 2) Coir Fibre Coir or coconut fibre is a natural fibre extracted from the husk of the coconut. You will often see it used in brushes, doormats, and floor mats. Coir is an excellent alternative to sphagnum peat moss, because it contains more nutrients and lasts longer. It is more expensive to purchase, but many gardeners feel it is a lot more sustainable. 3) Sand Sand is a core ingredient in potting soil, and we recommend using sharp sand which is coarse and sharp and enhances drainage and aeration as well as adding weight to the mix. “Builders sand is best avoided as it generally contains lime and is not as coarse as sharp sand and can therefore clog up potting mixes with its finer particles,” Roy adds. Do take care not to go overboard on the sand as this can make the containers too heavy to move. 4) Perlite Perlite is mined, expanded volcanic glass that has the appearance of white Styrofoam balls. Lightweight and sterile, perlite can hold up to four times its weight in water and is excellent for improving drainage. It is more expensive than sand, but its qualities may make it worth the extra expense. “Most tropical houseplants require free-draining substrate and an easy way to achieve this is by adding some orchid bark and perlite to the potting compost,” shares Sarah Gerrard-Jones, Horticultural Author and Blogger. 5) Vermiculite Vermiculite is an excellent alternative to perlite. It is a mined mineral which is then conditioned with heat which causes it to expand into light particles. Vermiculite increases the porosity of your potting soil, providing magnesium and calcium and increasing the water-holding capacity of your mix.1 6) Fertilisers You will need to add fertilisers to your peat-based DIY potting soil as the mix won’t naturally contain enough nutrients to support good plant growth. Stay away from synthetic fertilisers and instead opt for a natural fertiliser combining plant materials or animal by-products such as manure. 7) Limestone As mentioned, adding limestone can help balance the pH levels in your potting soil. We recommend using about a quarter of a cup per every six gallons of peat-based potting soil. 8) Garden Compost Homemade garden compost is a wonderful addition to your DIY potting soil. It has an excellent capacity for holding water and is high in nutrients. Including compost can play an instrumental role in promoting healthy plant growth – that said, we don’t advise using it for containers where you are seed-starting as it can be too heavy and prevent good growth. 9) Composted Woodchips By introducing composted woodchips to your homemade potting soil, you will increase the pore sizes, allowing for better water and airflow. It is imperative to note that, although the woodchips are slow to breakdown, they can decrease the nitrogen within the potting soil and we therefore recommend supplementing with blood meal or alfalfa meal. Composted woodchips are an ideal ingredient for growing shrubs and perennials. Once you have purchased the woodchips, you will want to allow them to compost for a year and you should be turning the pile at least every three weeks. Alternatively, composted bark can be purchased separately and used immediately in potting mixes. Go Potty For DIY Potting Soil Hopefully, this article has left you brimming with confidence to make your own DIY potting soil. The wonderful thing about it is that, once you get into it, you can really change and adapt your own potting soil brand to perfectly suit the plants you are keen to grow. Help your potted plants thrive with your own brand of potting soil Learning to make your own potting soil will teach you so much about your potted plants, flowers, shrubs and trees and will give you a real understanding of their specific, individual needs. Don’t be afraid to use a little trial and error; this is a rewarding process and will lead you to feeling like a much more confident and well-rounded gardener. So go ahead and get mixing the perfect DIY potting soil for your potted plants. References 1. Cation Exchange Capacity in Vermiculite. (2021, March 30). Dicalite Management Group. Retrieved March 14, 2023, from https://www.dicalite.com/2021/03/cation-exchange-capacity-vermiculite/
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Starting Your Own Compost Bin At Home - Make Sure You Get Your C:N Ratio Right
IN THIS GUIDE Composting Methods The Carbon:Nitrogen Ratio Turning & Aeration Wetness What Can You Put In A Compost Bin? How To Keep Your Compost Bin From Smelling Pests Earthworms Resolving Bad Smells Sun Or Shade? References You don’t really ‘use’ a compost bin you may think; all you do is throw clippings, vegetable refuse, and such in it, and that’s that…except that it isn’t. In order to make high-quality compost without running into trouble, you really have to ‘use’ your compost bin, and use it effectively. This means taking several measures. Composting Methods To begin with, two methods can be used to make compost: the Batch Method and the As-You-Go Method. Here’s how they work: The Batch Method is a two-step method such that first you prepare the pile by putting in the materials and contents that are to be composted, and then you ‘cook’ the whole thing as a batch. In contrast, As-You-Go is an iterative method in which adding composting materials and the ‘cooking’ occur without discrete steps as a single ongoing process. Compost bins are ideally suited to As-You-Go Style composting while compost tumblers are better for the Batch Method. As this is an instructional article about making compost in bins, our primary focus shall be on the As-You-Go Method. The Carbon:Nitrogen Ratio Effective usage of your compost bin requires that you get the Carbon:Nitrogen – C:N – Ratio right. For a compost bin the ideal C:N ratio is from 25:1 to 35:1.1 The C:N ratio is colloquially but incorrectly also called the ‘Brown-Green Mix.’ Be mindful that C:N and Brown-Green do not have a direct correspondence: ‘Green’ compost content has a fairly narrow range of C:N ratios between 10:1 and 30:1. ‘Brown’ content’s C:N ratio and, therefore, carbon content, varies widely. It ranges from 30:1 to 800:1!2 Also, where composting is concerned, ‘Green’ content includes that which is green in colour; however, material like tea leaves, coffee grounds, and manure are considered ‘Greens’ because of their C:N ratios. Two Simple Rules You can hit the desired C:N ratio by following two simple rules: Strive for a Brown/Green materials 70/30 mix: that is just over two parts Brown to every one Green.3 Be careful with woody and wood-derived materials; use these in very low quantities because they have an extremely high proportion of Carbon to Nitrogen. “I find if woody twigs don’t compost the first time round, I just add them back into the current compost pile to contribute to next year’s compost,” shares Master Horticulturist Roy Nicol. Turning & Aeration Turning and Aeration are crucial to making high-quality compost. The reason to turn and aerate a compost pile is that if it just sits then the material near the top will decompose at a faster rate while the material that is at the bottom, and which is being compressed by the pile’s weight, will decompose at a slower rate. Organic materials need air to decompose but materials that are in the middle of the pile or compressed at the bottom would be starved of air. Turning the compost pile means that there is no bottom layer and no top layer, and this agitation ‘fluffs up’ compressed materials and opens up air channels in them. Vigorous turning will also bring another benefit; it will tear and break up scraps and pieces. Cross-section of a compost bin that has not been turned Use A Handheld Aerator You will need to turn and mix up, and thus aerate, your compost pile by using a handheld aerator. Try to choose one that is right for you and also for your compost bin. If you want to be frugal and go low-tech, do as your grandpa did and use a pitchfork. Aerate around once a month. Also, do so when you add a fair quantity of material to your As-You-Go pile in the bin. You can insert your aerator through the built-in holes at the top and/or the sides of your bin. However, you probably will be more comfortable and will be able to do a better job of turning and mixing the compost if you open the lid and use the aerator through this (much) larger opening. “A common composting system has two or three compost bins (or bays in larger gardens,” shares Roy. “Once full, the compost is turned from one bin into another and a new pile started in the first bin. “The part-processed compost in the second bin has then been aerated and will decompose further, often being ready to use in 2-3 months.” Wetness The moisture content of the compost pile is another key to effective decomposition. The pile should remain damp and should never be allowed to dry out because if it does, ‘cooking’ will slow down and the pile will also decompose (more) unevenly. If, when turning the pile, you observe that it is dry, conservatively water it all over as you turn it such that it is well moistened and damp but not wet. What Can You Put In A Compost Bin? A bucket to collect and transport organic waste can be useful The short answer: anything organic, because it will decompose. “Compost as much garden and kitchen waste as possible,” says Garden Blogger Hannah Reid “There’s nothing more satisfying than making your own compost from this afterwards.” The best things to put in a bin are garden clippings and cuttings, vegetable and fruit waste, grass clippings, fresh leaves, dry leaves, mulch, kelp and other seaweed, hay, and straw. Try to chop up or dice big cuttings otherwise they will not decompose as rapidly as you would like. “As leaves normally become available in large quantities in the autumn, it’s best not to add these as a thick layer to the compost heap, as they decompose anaerobically, which is slower than the aerobic composting process,” says Roy. “Instead, leaves can be added to a separate bin made from chicken wire and after a year will have decomposed into a fantastic dark and friable material called leaf mould.” Household Waste In addition, you can put carefully-selected leftover food scraps, twigs, newspapers, rough (not coated or shiny) cardboard, manure, sawdust, wood chips, tea leaves, coffee grounds, old cotton cloth, eggshells, and peat moss. Do not add rice or grains, cooked or uncooked, or meat or dairy products. Rice and grains will bring rodents to your compost bin while meat and dairy will attract flies and may well putrefy instead of aerobically decomposing. Newspapers and cotton cloth should be torn into small pieces and soaked or wetted before being added to the bin to promote decomposition. All wood-based and wood-derived materials have a very high C:N ratio – 400:1 and higher – so be conservative when including such materials. Err on the side of too little of these than too much, otherwise the compost pile will remain dry, won’t heat up, and will decompose very slowly and very unevenly. Layering Materials How you arrange or layer these materials initially is of some importance. Put a layer of brown materials at the bottom followed by green materials and build the layers, spreading the additions as you go. Of course, when you turn and churn the pile, everything will get mixed but ‘layering’ is the way to start off on the right foot. Weeds Weeds are organic plant-based material but if you are new to composting or simply don’t have time for fussing, do not put any weeds in your compost bin. Weeds enjoy warm and rich composting materials so much that they will take root and grow in your compost pile! On top of that, if weeds go to seed as your compost ‘cooks,’ you could end up with weed seeds in your compost – which means that your nice new compost would sprout weeds. “I also avoid adding garden plants which self-seed freely such as Valerian (Valeriana officinalis), Forget-Me-Not (Myosotis sylvatica), Lady’s Mantle (Alchemilla mollis) or Granny’s Bonnet (Aquilegia vulgaris),” adds Roy. “Different gardeners have different tolerances for these plants popping up around the garden though!’ The way to make sure that weeds do not germinate and turn into compost is to ‘pre-bake’ them, or to use the Batch Composting method, turn the pile very frequently, and even monitor the temperature at its centre to be sure it does not drop below 65°C. And for all that, you should not put pernicious weeds such as Bindweed, Ground Elder, Mare’s Tail or other perennial weeds with strong roots such as Dandelions or Nettles in your compost pile at all. Manure Fresh manure from herbivores such as horses, cattle, sheep, goats and rabbits can be added to the compost bin in quantities in proportion to the size of the pile. This material acts as an accelerant to the composting process due to its microbial content and increases the biodiversity of the compost pile. The high nitrogen content means it cannot be used as mulch immediately as it would burn green foliage. Care should be taken if manure has a high proportion of slowly decomposing ‘brown’ bedding such as sawdust or paper pellets and only added in thin layers. What To Put In A Compost Bin When Starting “If you have a compost bin, you shouldn’t have to buy compost,” shares Edible Bristol’s Sara Venn. “There’s always something you can find around you that you can add to it, so you really should consider starting your own.” A very good mix to start off a compost bin would comprise of vegetable and fruit refuse, grass clippings, tea leaves and coffee grounds, chopped or torn-up dried leaves, wetted old cotton cloth or some shredded and wetted newspapers. While these limited materials in the right proportions make for a very good Brown-Green mix, they are also very readily accessible. How To Keep Your Compost Bin From Smelling To keep your compost bin from smelling, first, you need to make sure that the pile will decompose evenly and aerobically, and not unevenly or anaerobically. To achieve this rather important end, the pile needs to have air circulating within it – even right at the very bottom. Turning and aerating the pile with an aerator will ensure that there is no ‘bottom layer’ as such because the pile gets turned and churned. It also ensures that all the bits and pieces get separated which means that air channels open up throughout the pile, increasing airflow. Second, your pile’s Carbon:Nitrogen balance should not tip over too far towards Nitrogen which can and does happen when too much ‘Green’ and too little ‘Brown’ is added.4 Be sure that you keep adding a sufficient amount of ‘Browns’ to balance whatever ‘Greens’ you add. Finally, some materials are smelly to begin with and are also more likely to putrefy and emit foul odours. These include meat and dairy products and, yes, manures. You can exclude such materials without any negative impacts on your compost pile. Pests Grubs Rose chafer larvae in a compost pile – yuk! First, think it over. There are grubs, and then there are grubs. Many of them, like earthworms and microbes, are actually beneficial to your compost pile without ever being harmful, even after you use the compost in your garden. Grubs burrow and tunnel through the pile thereby creating air-channels and doing some of the aeration for you; futhermore, like microbes, many grubs feed on organic materials and decompose them. Now if you have identified pernicious grubs such as vine weevils that may harm your garden, if your pile is simply infested with grubs, or if it has maggots, then you would need to get rid of them. Nematodes Buy or order a supply of Beneficial Nematodes, these are available at garden centres and online sellers. Follow the instructions and introduce the Nematodes into your compost pile. Goodbye, grubs. Birds You could also try to put a bird feeder very close to your compost pile. The birds that you attract may go on to feed on the grubs in your pile! Flies To begin with, keep the lid tightly closed. If your compost bin is a jerry-rigged affair and has no lid then cut out the appropriate size of heavy-duty but fine wire mesh such that you can bend the mesh over the rim of the bin and secure it. You will also need to cover the side air vents with a mesh netting. Flies are drawn to food waste, therefore push all food waste (and whatever else may attract flies) to the middle of the bin. Do not leave such materials at or near the surface. If you are developing a serious problem with flies, eliminate food waste altogether. Additionally, after turning the pile put a thin layer of grass clippings on top; this will not draw any flies. Rat-Proofing As the first step, you can ‘rat proof’ your bin by simple dint of using an all-solid bin made of hard materials and always keep the lid tightly closed such that it cannot be dislodged by these clever and persistent rodents. Cover up any side vents with rat-proof wire netting. You can ‘rat proof’ your bin’s interior by not adding any materials that would attract rats. These include leftover food scraps, meat, dairy, and eggshells – and you can live without these in your compost pile so nothing’s lost. To play it safe, keep the pile very much on the damp side. Rats will take to a dry’ish compost pile but not to a damp one. Put the bin on a concrete slab in an open, unsheltered area that does not provide any cover. Install an 11-watt daylight LED near the bin and keep it on from evening to dawn. You may also consider doing what our ancestors used to do in mediaeval times: keep a good ‘mouser.’ If you take all these measures you should never have any rats in or near your compost bin. Earthworms You don’t need to put earthworms in your bin, but you certainly may. If you want to put worms in your compost bin, put in red wriggles. They are perfectly adapted to the conditions of a compost bin and can be seen as “Mother Nature’s Composter”. As for earthworms, they are more sensitive to the highly variable conditions of a compost bin. Actually, if your compost pile offers conditions favourable to earthworms then they will make their way to it themselves but you can give it a shot and dump in some earthworms and see what happens. If they thrive in your compost bin you’ll have lucked out twice over. First, earthworms, like grubs, burrow and tunnel through the compost pile. In so doing they too create air channels inside the compost pile, aerating it.5 Second, earthworms consume much of the materials in the pile. What they excrete, called ‘castings,’ is rich in micronutrients and nitrogen, and is one of the bases for high-quality compost.6 Composting with the aid of worms is known as ‘vermicomposting.’ Resolving Bad Smells Compost bins may smell a wee bit. Depending on what has gone into a Batch Style compost heap, it can smell a little initially. And depending on what you may add to an As-You-Go Style compost pile it too may smell a bit. Then again, just as often a well-maintained compost bin will give off a warm, musty, earthy odour that may even be quite pleasant. Well-tumbled compost in properly-used and aerated bins should not smell particularly bad at all. But sometimes compost bins do smell bad, and when this happens it signifies that something has gone wrong. One reason behind it could be that the compost pile, instead of decomposing aerobically, is putrefying – decomposing anaerobically, i.e. without oxygen which points to inadequate aeration. Another reason behind it, especially if the bad smell is like ammonia, is a seriously out-of-whack Carbon:Nitrogen ratio skewed in favour of Nitrogen. And if you’ve been naughty and went and threw leftover meat or dairy into your bin, well… Sun Or Shade? As a general rule, you should place your bin in the sun, but in practice it depends on a couple of factors. Direct sun and the resultant heat speed up the process of decomposition, and they aid in ‘cooking’ the pile so this major benefit is a compelling reason for siting your bin in the sun. Except that direct sun and high heat also dry a compost pile – it needs to be damp. Thus, direct sun and high heat also eventually slow down the process of decomposing by drying out the pile! You can put your bin in the sun and easily work around this drawback by monitoring the pile for dryness and watering it regularly. On the other hand, if you are specifically doing vermicomposting, then you will need to avoid hot sun and keep your compost bin in mostly shade because typically worms cannot tolerate high heat. Like many things in life, opt for a happy medium and try to locate your compost bin where it gets a good amount of sun in the morning and late afternoon but not the hot midday sun. For more composting guidance see also: how to make a home compost heap. References 1. Akratos, C. S., Tekerlekopoulou, A. G., Vasiliadou, I. A., & Vayenas, D. V. (2017). Cocomposting of olive mill waste for the production of soil amendments. In Elsevier eBooks (pp. 161–182). https://doi.org/10.1016/b978-0-12-805314-0.00008-x 2. Browning, S. (n.d.). Garden Compost. Retrieved June 26, 2023, from https://extensionpublications.unl.edu/assets/html/g2222/build/g2222.htm 3. Composting At Home | US EPA. (2023, June 14). US EPA. Retrieved June 23, 2023, from https://www.epa.gov/recycle/composting-home 4. Troubleshooting Your Compost Pile. (n.d.). LSU Ag-Center. Retrieved March 20, 2023, from https://www.lsuagcenter.com/NR/rdonlyres/BCC96EDA-75F7-4F08-9C81-1ADA8C167D49/2182/pub2517compost2.pdf 5. Discovering Earthworms Online. (2021, June 17). Earthworm Society of Britain. Retrieved March 20, 2023, from https://www.earthwormsoc.org.uk/DiscoveringEarthwormsBlog 6. All You Need to Know About Earthworm Castings. (n.d.). Pennington. Retrieved March 20, 2023, from https://www.pennington.com/all-products/fertilizer/resources/earthworm-castings-all-the-goodness-without-the-goo
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