Growing
'Mimosa Tree' Is The Name Used For Two Non-Native Species - These Are Their Pros And Cons
IN THIS GUIDE Overview Pink Silk Tree Pros Cons Silver Wattle Pros Cons Other Flowering Trees Nitrogen Fixing Trees Trees With Edible Yields The name ‘Mimosa Tree’ is the common name for two non-native tree species – Albizia julibrissin and Acacia dealbata, even though neither belong to the Mimosiae genus. Online and in books, you will frequently hear horror stories about these plants, which can be hugely invasive in some areas. You may also read, however, about how they can help in sustainable design and ecosystem restoration… However, the pros and cons of these trees very much depend on where they are grown. Overview Botanical Names Albizia julibrissin / Acacia dealbata Common Name(s) Mimosa Tree, Pink Silk Tree, Silver Wattle, Blue Wattle Plant Type Tree Native Area E. Transcaucasus to Japan and South East Australia Hardiness Rating H3-H4 Foliage Deciduous / evergreen Flowers Yellow / pink-white blooms When To Sow April, May, June / September, October Flowering Months March to April or July to August When To Prune May / October While Mimosa trees can certainly bring serious issues for local ecosystems where they become invasive, this is typically not an issue in UK gardens, where these trees are much harder to grow. Still, though they can bring certain benefits, there are a number of reasons why they may not be the best choices for many UK gardens (which have nothing to do with their potentially invasive nature). Read on to learn a little more about the pros and cons of both of these mimosa trees: Pink Silk Tree Botanical Name: Albizia julibrissin Albizia julibrissin, also known as ‘Pink Silk Tree’ and commonly referred to as ‘Mimosa’ in the US, certainly is an attractive flowering tree. It is a deciduous tree with rose-pink fluffy flower heads which open in the summer months, and features interesting and exotic-looking bipinnate leaves. This plant is native to Ethiopia, Iran to Japan and China, though it has extensively naturalised elsewhere. Pros Nitrogen Fixation One of the main reasons why this can be a very useful plant in many regions is that. because it belongs to the Pea family Fabaceae, it is a nitrogen-fixing plant, meaning it deposits nitrogen in the soil it grows. As it can cope with a huge range of different soil and climatic conditions, this can make it a useful pioneer plant, which can be used to reclaim degraded landscapes and as a key species in forest gardens and agroforestry schemes. Not Typically Invasive (In The UK) This tree is H4 hardy and can be grown in some UK gardens with sufficient sun, warmth and shelter. However, in the climate of the British Isles, it rarely sets seed. This means that it is not as problematic as an invasive as it can be in parts of the US, and other areas. In southern, sheltered gardens, this can be an interesting option to consider – the tree is a suitable size for small gardens so can work well in some sheltered urban plots, and it is ideal for training against a sunny south-facing wall, or for container growing. Honey Fungus Resistance One other interesting plus point of this tree is that it is notably rarely affected by honey fungus. So for gardeners who have had issues with this fungal disease, it could be a good choice. Cons It really only succeeds in the very mildest parts of the British Isles without protection, or being brought under cover during the winter months. Hardiness If you do not have a particularly warm, sunny and sheltered garden then this may not be the easiest plant to grow and lower maintenance alternatives may be a better choice. Remember, this is a non-native plant and native options can often be better for your garden. Alternating spells of mild and cold weather can damage the top growth, and though these can and do often regrow from the ground when damaged by frost, the damage can be unsightly. “Newer growth over the summer can become damaged by winter frost, but these stems can be pruned out in the late spring to improve the appearance of the plant which produces the fern-like foliage from the early summer,” says Master Horticulturist Roy Nicol. It is also worth noting that though it is notably resistant to honey fungus, it can be affected by other diseases, such as verticillium wilt. Tendency To Spread Though the plant will not usually set seed in the UK, it can still spread. Plants often produce suckers and send up saplings, sometimes quite far from the parent tree. The strong root system can make these difficult to remove. The strong root system can crack concrete pavers or driveways, damaging the infrastructure in your garden. Though of course, this is not an issue when grown in containers. Mess below the tree is also a concern to some – flowers dropping off the tree can be a problem for some very neat and tidy gardeners. Silver Wattle Botanical Name: Acacia dealbata Acacia dealbata, also known as mimosa, silver wattle or blue wattle, is also sometimes grown in the UK. It is native to Tasmania and parts of mainland Australia. Pros Nitrogen Fixing This plant is H3 hardy, but where it can be grown, this is another useful nitrogen-fixing plant. Remember, nitrogen-fixing plants have symbiotic relationships with bacteria in their root nodules which can turn nitrogen from the air into nitrogen in the soil. Some of the nitrogen is used by the plant itself, but some may also be taken up by other plants in the vicinity. Drought Tolerant Like the above, this is a good pioneer plant for some climate zones. It is drought-tolerant and may be a good choice for lower rainfall areas. Preventing Soil Erosion This tree also has an extensive root system, which helps prevent soil erosion. So it can be a useful addition in areas with poor, light soils which can easily be eroded. Like the above, this mimosa is also a good choice for small spaces, and it can also be grown in containers, or trained against sunny, south-facing walls. The flowers of silver wattle are fragrant, so can be pleasant when located close to windows or seating areas, and the flowers are edible too. Cons Hardiness & Soil Requirements Like silk trees, silver wattle can only be grown without winter protection in milder parts of the British Isles, and requires a sheltered position. So again, it is not the most low-maintenance choice and you may find many of the same benefits with other lower-maintenance trees and plants. It is also worth noting that while Acacia dealbata can work well in many different conditions, it is not suitable for heavy clay or limey soils. Remember, as an H3 hardy plant, this tree must usually be moved under cover in winter unless you live in a particularly mild and warm part of the British Isles. They really do need hot, sunny summers to mature and flower successfully. Invasiveness Mature specimens sucker very freely, just like the Albizia julibrissin, so this too can be a plant that can spread and pose a problem in your garden. Mess dispersed below this tree may also be annoying for neat and tidy gardeners. While both of these mimosa trees can bring benefits, neither may be the right choice for most UK gardeners. Here are some alternatives to consider: Other Flowering Trees Flowering Cherries Crab apples Amelanchier Magnolias Paulownia Nitrogen Fixing Trees Laburnum tree Some good nitrogen-fixing options for growing in the UK include: Alders Common laburnum Laburnum x watereri Laburnocytisus adamii Caragana arborensis Trees With Edible Yields As well as the usual range of fruit trees including apples, pears, plums, cherries and more, you can also consider growing trees with edible leaves, such as: Hawthorn Lime / Linden Beech Birch Mulberry Even if mimosa trees are not the right choice for your garden, you should still be able to find other trees which provide many of the same benefits, without the cons mentioned above.
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Growing Medlar: An Unusual Choice As A Fruit Tree, But It Can Be A Rewarding Plant
IN THIS GUIDE Overview Why Grow Medlar? How To Grow Medlar Medlar Care Common Problems References It must be said that this plant is fairly unusual. It’s a tree that can also be grown as a shrub, and it bears an edible fruit, but here’s the thing: the vast majority of people in the UK won’t have tried – or even heard – of it! However, Mespilus germanica, more commonly known as medlar, is a rewarding and interesting plant to grow. We’ll hold off from saying the fruit is delicious because it’s something of an acquired taste, but it is a new and potentially intriguing flavour. Overview Botanical Name Mespilus germanica Common Name(s) Common Medlar, Dutch Medlar Plant Type Fruit Tree / Shrub Native Area Europe, Middle East Hardiness Rating H6 Foliage Deciduous, long leaves Flowers White blossom in spring When To Plant January, February, March, November, December Harvesting Months November, December When To Prune February, March Medlar, or Mespilus germanica, is an ancient fruit that bears some resemblance to pomegranate, and tastes to some a little like quince. The fruits are brown or yellow, and usually measure between 2.5-5cm. Each fruit has a cluster of five ‘petals’ around its top, lending them a distinct aesthetic when compared to other common garden fruits. As we mentioned, medlar can grow as a tree or as a shrub. Trees of the original species Mespilus germanica will grow up to eight metres; grafted trees and shrubs will clock in a fair bit smaller. The tree is known for growing in a lopsided way, to the point that it can be pulled down by its own weight. Although it may not be relevant for the first few years, bear in mind that you may need to stake your tree to support it in its later years or carry out formative pruning as the tree grows to help prevent too much growth on one side. Why Grow Medlar? The fruits are edible, as we’ve said, but they have a fairly unusual taste. If you’ve ever tried quince it’s in that ballpark, but not quite the same. Other people say it evokes apple sauce flavours, but opinions on the exact nature of the taste (and its appeal!) vary wildly. The main reason we recommend medlar is novelty – it’s something you won’t find in supermarkets or even grocery stalls at markets. Most people won’t have tried it, making it a good conversation starter and point of interest in your garden. Given the differing opinions on the flavour, you may not be convinced to grow medlar based on the eating opportunities alone. And if that’s the case, you’re in luck because this is also an attractive ornamental plant that will provide something a little different for your outdoor space. How To Grow Medlar Sowing It’s possible and not too difficult to grow this plant from seed – sow in early spring and start in small pots. Ensure they have moist soil, and are kept in a dark, cool spot. Seeds will take around five weeks to germinate and should be hardened off before being planted out. “Bear in mind this will produce the original species tree Mespilus germanica which is likely to grow into a large tree up to 8m, so enough space needs to be allocated for it to grow,” adds Roy Nicol, a Master Horticulturist. Planting Out You can buy medlar as a shrub if you’re not interested in growing it from seed. Plant this out any time between November and March, and use a stake to keep the fledgling tree supported for the first five years or so. Medlar can be grown in containers as well as in the ground – go for a big pot to give the plant ample space to grow. Again, plant out in November through March. Where To Grow Choose a spot with deep and fertile soil; drainage needs to be good; full sun is best for medlars but partial shade will work as well. It’s important to choose a spot that won’t be exposed to strong winds, as the leaves and floral bloom of medlar are both easily damaged. Medlar Care Fertilising Mulch the area at the base of the plant, and keep the soil fed well to ensure the plant is well nourished. Add a handful of high potassium fertiliser each spring, such as granular Sulphate of Potash, one handful for each metre of soil surface. Or, if growing on grass rather than just soil, use a handful and a half. Watering Medlar isn’t overly thirsty, except in dry spells. Be extra vigilant in the first four years of the plant’s life, making sure to keep it well watered during particularly dry patches in this period. Pruning To keep your medlar in prime condition you’ll need to remove weak and dead branches. Winter is the best time to prune, when the leaves have fallen. Depending on whether you’re growing as a tree or shrub, your priorities when pruning will be different. For a tree, your priority is establishing a balanced branch system to encourage efficient fruiting and to avoid problems later in the tree’s life. The method for pruning young fruit trees is actually quite involved (medlars are pruned in the same way as apple and pear trees) and because it won’t be relevant to everyone reading this piece we’ll link you to a great resource instead. If you’re growing a medlar tree and need advice on pruning it during the formative years, check out this great guide from the Royal Horticultural Society.1 Harvesting Bear in mind that it will take a few growing seasons to bear fruit: between three and five years. When your medlar is bearing fruit, October and November are the best times for harvest. You can leave fruit on the tree to ripen for a little longer, just watch out for frost as this will push them past their best. Pick your medlars when the fruit is rock hard, then let it ripen before eating. There’s a special name for this process which you may not have heard before: bletting. When bletting fruit, you’re letting it rot slightly before you eat it – this sounds a little grim but trust us – it’ll get you the best results!2 With medlar you eat the filling but not the seeds. Common Problems Medlar is prone to visitations from certain garden pests, but thankfully they’re not too difficult to keep in check. Here’s what you need to keep a lookout for: Winter Moth Caterpillars These creatures enjoy eating and generally damaging the leaves of your medlar, which can disrupt its ability to photosynthesize. Picking off the caterpillars should be enough to deter them, and keep a vigilant eye to make sure they don’t return. “If some damage is experienced from these caterpillars during a growing season, a grease band can be placed around the trunk in October until the spring to prevent the wingless female moths from travelling up the tree and laying eggs in the canopy,” says Roy. Birds Flying visitors are also prone to be attracted by the promise of fresh fruit. There are visual ways to deter birds: scarecrows and such. You can also use anti-bird gel, spikes, or ultrasonic repellers. Recordings of bird distress calls work well, too. You’ve got a few options and the most suitable will depend on your garden and your preferences. While it may take a little getting used to – and be forewarned the flavour isn’t for everyone – the potential rewards of growing this plant far outweigh the downsides. Even if you’re not a fan of the taste of medlar you’ve still got an attractive and distinctive plant growing in your garden. Whatever your reasons, we hope you enjoy growing medlar, and that you found this guide useful. References 1. Apple and pears: pruning newly planted trees. (n.d.). Royal Horticultural Society. Retrieved March 21, 2023, from https://www.rhs.org.uk/fruit/apples/pruning-new-trees 2. Gorvett, Z. (2021, March 25). The forgotten medieval fruit with a vulgar name. BBC Future. Retrieved March 21, 2023, from https://www.bbc.com/future/article/20210325-the-strange-medieval-fruit-the-world-forgot
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Growing Hazelnut Tree - 'If I Could Recommend Just One Native Tree, This Would Be It'
IN THIS GUIDE Overview Why Grow Hazelnuts? How To Grow Hazelnut Trees Hazelnut Tree Care Harvesting Hazelnuts References The hazelnut tree is one of the most useful and valuable nut-producing trees in the UK, and it can be a useful addition to many gardens. If I could recommend just one tree for UK gardeners looking for trees with edible and useful yields, then I think that the hazel tree would be it. Whether you are looking for a tree to use as an individual specimen tree, looking for a tree for coppicing, looking for lower canopy trees for forest gardens, or orchards – or even looking for trees to use in mixed native hedgerows – the hazel is an excellent choice. It is one of our favourite native trees – for a range of reasons. Overview Botanical Name Corylus avellana Common Name(s) Hazel(nut) Tree; Common Hazel Plant Type Tree / Hedging Native Area Europe & W. Asia Hardiness Rating H6 Foliage Deciduous Flowers Dangling Catkins When To Sow January, February, March, November, December Harvesting Months September, October Pruning Months January, February, March, November, December Our native hazel tree is Corylus avellana; the Common Hazel is native to all of Europe and even some of West Asia – stretching all the way to the Caucusus.1 Common hazel It naturally grows in woods, especially on the slopes of hills, forming small trees up to around 6m high and 3m wide, though it can easily be kept much smaller when pruned and shaped as part of a wild hedgerow, or when used in a coppicing system. This is an extremely hardy tree that can cope well with a wide range of conditions here in the UK. Corylus maxima Corylus maxima is another type of hazelnut tree that may be of interest. It is a Hazel species with much in common with C. avellana – but generally produces more sizable nuts. If growing hazel for edible nuts, therefore, hybrid types C. avellana x C. maxima can be good choices. However, yields of both these edible nuts are usually better in more southern reaches of the British Isles than they are further north. Corylus avellana ‘Contorta’ C. avellana ‘Contorta’ (corkscrew hazel) is another interesting option for your garden. ‘Contorta’ It is chosen for its ornamental twisting stems rather than its yield, but can be a good choice to consider if you are just looking for a small ornamental tree for your garden. Why Grow Hazelnuts? Hazelnuts are one of the very best perennial protein and oil crops for temperate climates. C. avellana catkins If you are looking to branch out beyond traditional annual food cultivation and look into more sustainable, perennial food-producing options, then the hazel tree is an excellent option to consider. Yields & Uses Yields can vary, and wildlife can be a challenge – often getting to the nuts before you can, but if you want to grow nuts in the UK, hazels are one of the top trees to consider. Hazel nuts are edible, of course, but can also be used in other ways – for example, the nuts can be rubbed on wood to release the oil and polish it. The non-drying oil derived from the seeds is also used in paints and cosmetics. Even if you are not looking to produce nuts in your garden, hazel trees can still be a very good choice. Wildlife Benefits The hazel is a wonderful, wildlife-friendly landscaping tree – attracting and supporting a wide range of native species. This tree can be coppiced and so can be great in carbon gardening and long-term, sustainable garden systems. If you have a vegetable garden, you will no doubt be able to find plenty of ways to use coppiced hazel in supporting your plants. Hazel trees can also be very useful for native hedgerow schemes. It works well in combination with other native species such as elder, blackthorn, hawthorn, native roses etc. All hazel trees, however, have ornamental appeal – especially when they bear their dangling catkins in late winter or early spring. How To Grow Hazelnut Trees Hazels can grow in full sun or light, dappled shade. They are H6 hardy and can grow across most of the British Isles. Soil Requirements Generally unfussy about their growing conditions, they will unfortunately not grow well in acidic soil, but can cope well in neutral, alkaline or even very alkaline soils. They can thrive in most soil types, but will do best in a good quality loam, which is neither low in nutrients nor excessively high in fertility. Yields are highest where the soils are neither particularly poor nor particularly rich. In clay soils, the area should be amended with plenty of organic matter to improve drainage, since the hazelnut tree likes moist yet relatively free-draining conditions. Exposure Hazelnut trees can tolerate wind exposure, but will not typically thrive in a maritime location. You can grow a hazel as a stand-alone tree, even in a smaller garden, while you can also consider growing it as an under-storey tree or coppice shrub in an existing woodland area or in a forest garden design. As mentioned above, you can also use it in hedgerows. Results (nut yields) will generally be best if you plant more than one hazel. Planting Like other trees, hazels are often bought as bare-root specimens which can be planted out over the dormant period. However, hazels can withstand transplantation well, so you can also choose a mature specimen if you want to achieve a more established garden more quickly, and plant that out in spring or early autumn. Hazels can also be grown from seed, though most home gardeners will find this a challenging proposition, and of course it will take a long time. Hazels grown from seed are typically transplanted into their growing position when around 2 years old, then, for coppicing, left for 4 years or so before they are cut to the ground to encourage straight coppice stems to form. Hazelnut Tree Care Hazels will not typically require a lot of care, though young trees and shrubs should be well watered during dry periods until they are established. Mulching It is a good idea to mulch around a newly planted hazel tree with wood chip, bark, or other organic material. Woody mulches will encourage a fungal soil environment, which can also help trees to become established. Protection It may also be a good idea to protect young trees from deer and other foragers with a wire cage or a tree protector in areas where they may be vulnerable. If you want to collect the edible nuts then you may find it challenging to protect the tree from squirrels and other wildlife. A fruit cage or other protection might be beneficial if you wish to grow nuts in any quantity. Diversity will also help make sure there is plenty of other food around for foraging creatures – though of course won’t keep them away entirely. Pruning / Coppicing Pruning or coppicing hazel will depend on where and how exactly you wish your hazel to grow. You can prune hazel lightly to keep it in shape, or largely leave it alone. “In a small garden the largest stems can be pruned out in alternate years in spring once the catkins have dropped, keeping the plant size restricted,” says Horticulturist Colin Skelly, who has been certified in tree inspection by the Arboricultural Association. “These stems can then be re-used as poles elsewhere in the garden,” advises Colin. If growing it in a hedgerow, you can also leave it wilder or keep it more in check, or you can coppice hard in a regular coppicing system. Cutting hazel to the ground every 5-10 years is typical, usually in spring after the catkins have dropped. This will encourage the hazel to take on a more shrub-like form, with plenty of long, straight stems that you can use. Harvesting Hazelnuts Hazelnuts are harvested from September, as long as the wildlife has not gotten there first. The nuts are ripe when the outer casing begins to turn yellow. The nuts can be eaten raw, roasted, or used in a range of different ways. You can store the nuts in their casing for up to around a year if you can keep them safe from mice and other pests. But remember, even if you do not get any nuts, hazelnut trees can still provide a range of other yields and are very useful additions to your garden. References 1. Corylus avellana. (n.d.). Kew Royal Botanic Gardens. Retrieved March 16, 2023, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:295446-1
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Use Any Of These 20 Options For Growing Under Trees Says Peter Lickorish
IN THIS GUIDE 1) Elephant Ears 2) Bleeding Heart 3) Daphne 4) Fuchsia 5) Plantain Lilies 6) Lily Of The Valley 7) Lungwort 8) Japanese Spurge 9) Periwinkle 10) Primrose 11) Garden Solomon’s Seal 12) Viburnum 13) Coral Bells 14) Spotted Deadnettle 15) Cranesbill 16) Columbine 17) Bluebells 18) Cyclamen 19) Foxgloves 20) Weigela Tips For Growing Under Trees References Beneath the boughs of a tree may be one of the most challenging places to cultivate growth in your garden, but there are plenty of plants that will oblige. Trees offer many benefits for a garden – their height and canopy can provide shade from the sun and shelter from the rain, alongside the obvious aesthetic advantages they bring. However, those two practical selling points can become drawbacks when it comes to planting in their vicinity – since the lack of sunlight and moisture can inhibit the growth of many species. “Some trees are more likely to have shallow roots, such as cherries and rowans, so planting under these is more of a challenge,” says Master Horticulturist Peter Lickorish. “Damage to the roots may also cause suckering. To avoid drawing the eye too much away from the tree above, a simple mass of Hakone grass (Hakonechloa) can work really well to blanket the ground, if the canopy above is not too dense.” Fortunately, there are still an abundance of options that will do well in such a situation. The following list is largely suitable for growing under any kind of tree coverage, but it’s always best to consult the specific care instructions associated with your plant of choice should any doubt remain. 1) Elephant Ears BOTANICAL NAME: BERGENIA HARDINESS RATING: H7 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SPRING With their large, glossy leaves and sprouting clumps of colourful flowers, Bergenias are among the most loved flowers in any garden. They can handle shade particularly well, while some strains can even benefit from poor quality soil by giving their leaves a reddish hue in autumn and winter. What’s more, the fact that waterlogged soil and strong winds can harm their growth make sheltered planting ideal for Bergenia. The rock provides that succour for the Elephant’s Ears variety pictured above, but a tree would do the job equally well. 2) Bleeding Heart BOTANICAL NAME: DICENTRA / LAMPROCAPNOS HARDINESS RATING: H6 PREFERRED SUNLIGHT: PART SHADE FLOWERING SEASON: SPRING / SUMMER The delicately pendulous blooms of bleeding heart (or dicentra, if you want to be more formal) make them an instant showstopper to any environment they adorn. Although their heart-shaped blossoms are undoubtedly the main attraction, they’ll even provide intrigue when not in bloom through the intricately divided nature of their foliage. While most species will do just fine under the boughs of a tree, some hybrids do demand more sunny locations, so check before planting. 3) Daphne BOTANICAL NAME: DAPHNE HARDINESS RATING: H4 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: WINTER / SPRING Available in both deciduous and evergreen forms, daphne is a large genus of shrubs that are characterised by fragrant floral blooms and bright berries. While almost all of them are easy to cultivate in your garden regardless of the conditions they’re placed in, some can grow up to 1m or more in height, which could interfere with the lower branches of the tree above them. Since they often don’t take kindly to pruning, it’s advisable to opt for a smaller specimen when choosing a daphne for your garden. 4) Fuchsia BOTANICAL NAME: FUCHSIA HARDINESS RATING: H4 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SUMMER / AUTUMN Originally hailing from Central and South America, fuchsia plants have brightly coloured petals to attract the interest of hummingbirds in their native setting.1 Cross-breeding has produced a wide variety of different hues and combinations today, while their propensity to bloom right through summer makes them a firm favourite with UK homeowners. They don’t like too much sun, making them an ideal candidate for a display beneath a tree, but they do demand moist soil at all times – so be sure to prevent their feet from drying out. 5) Plantain Lilies BOTANICAL NAME: HOSTA HARDINESS RATING: H7 PREFERRED SUNLIGHT: PART SHADE FLOWERING SEASON: SUMMER Not all plants are favoured for their flowering splendour. Although some varieties of hosta do have blossoms, it’s certainly their foliage which is guaranteed to catch the eye. With hundreds of different species available, you can plump for hostas with wide, variegated leaves or small, dainty alternatives, while their colours can range from lush deep greens to sullen greyish blues to even bright whites. They can survive drought but will do best when given a hearty drink, so prevent them from drying out to achieve optimum results. 6) Lily Of The Valley BOTANICAL NAME: Convallaria majalis HARDINESS RATING: H7 PREFERRED SUNLIGHT: FULL SHADE FLOWERING SEASON: SPRING Despite its name, Lily of the Valley is perhaps more commonly found in woodland than valleys. Given its capacity to grow in even the darkest recesses of a forest, it should have no problem handling a shady spot in your back garden. The dainty blossoms look like they could serve as umbrellas for a fairy goddess, while the intoxicating fragrance they produce might suggest a fragile creature – but Lily of the Valley is hardy and fast-spreading, so it will provide adequate ground cover beneath your trees year after year. 7) Lungwort BOTANICAL NAME: Pulmonaria officinalis HARDINESS RATING: H6 PREFERRED SUNLIGHT: FULL SHADE / PART SHADE FLOWERING SEASON: SPRING Also known as pulmonaria, lungwort is so named for the shape of its leaves. Nonetheless, don’t let its slightly distasteful moniker blind you to its charms. Offering a colourful range of bee-friendly flowers atop silver-flecked foliage, this British native requires very little in the way of maintenance from you. As you can see in the image above, it’s perfectly capable of flourishing when nestled in the base of trees, too. 8) Japanese Spurge BOTANICAL NAME: Pachysandra HARDINESS RATING: H5 PREFERRED SUNLIGHT: FULL SHADE FLOWERING SEASON: SUMMER Pachysandra comes in all shapes and sizes, from low but dense ground cover to clumped shrubs as pictured above. What almost all varieties share in common, however, is the attractiveness of their foliage. Flowers will appear during the warmer months on most specimens, but it’s the thick patina on its leaves that make it stand out from the crowd. Pretty much all types of pachysandra will thrive in shaded conditions, though low-lying varieties may become invasive if not kept under control. 9) Periwinkle BOTANICAL NAME: VINCA MINOR HARDINESS RATING: H6 PREFERRED SUNLIGHT: ANY FLOWERING SEASON: SPRING / SUMMER Periwinkle is another plant whose progress must be closely monitored to avoid it spiralling out of control, since it just loves to spread out and invade the personal space of its neighbours. Having said that, it’s the perfect choice for a shaded spot beneath a tree where the soil is so eroded that nothing else will grow. Plus, the pretty flowers that it produces (in a range of colours, depending on the variety selected) will add intrigue come springtime. 10) Primrose BOTANICAL NAME: PRIMULA HARDINESS RATING: H7 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: WINTER / SPRING The above shot of a single primrose flower pluckily shooting forth from the immediate vicinity of an aged and mossy tree is the ideal illustration of their determination and staying power in even the most adverse of conditions. Indeed, it’s most at home in such situations, given that its natural habitat is the forest floor. Some varieties will begin to bloom before almost anything else in your garden and provide months of aesthetic value. 11) Garden Solomon’s Seal BOTANICAL NAME: Polygonatum x hybridum HARDINESS RATING: H7 PREFERRED SUNLIGHT: ANY FLOWERING SEASON: SPRING Solomon’s seal, or Polygonatum x hybridum to give it its Latin name, is a favourite among English cottage gardens and wild woodlands. It favours darker and cooler climes, meaning the nether reaches of a tree are the ideal spot for it, while the aesthetic attributes it brings are a huge draw for any horticulturist. The foliage is impressive enough itself, with paired oval leaves lining its graceful, drooping stems. However, the bell-shaped blooms, white in colour with a green tip, are what really sets it off – especially when paired with others on this list, such as Lily of the Valley or bleeding heart. 12) Viburnum BOTANICAL NAME: Viburnum davidii HARDINESS RATING: H5 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SPRING There is an incredibly diverse array of viburnums to choose from, with large deciduous shrubs and smaller evergreen perennials all on offer. The pictured variety above is Viburnum davidii, which provides the holy trinity of blossoms, berries and interesting foliage all in one. Dark leathery leaves provide the backdrop to tiny white flowers, while female specimens will supplement those twin advantages with metallic-looking berries when pollinated. Best of all, they’ll grow under your tree with minimal encouragement. 13) Coral Bells BOTANICAL NAME: HEUCHERA HARDINESS RATING: H6 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SUMMER 14) Spotted Deadnettle BOTANICAL NAME: LAMIUM HARDINESS RATING: H7 PREFERRED SUNLIGHT: FULL SHADE / PART SHADE FLOWERING SEASON: SUMMER 15) Cranesbill BOTANICAL NAME: Geranium sylvaticum HARDINESS RATING: H7 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SPRING / SUMMER 16) Columbine BOTANICAL NAME: AQUILEGIA HARDINESS RATING: H6-7 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SPRING / SUMMER 17) Bluebells BOTANICAL NAME: Hyacinthoides non-scripta HARDINESS RATING: H6 PREFERRED SUNLIGHT: PART SHADE FLOWERING SEASON: SPRING 18) Cyclamen BOTANICAL NAME: CYCLAMEN HEDERIFOLIUM HARDINESS RATING: H5 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: WINTER / SPRING 19) Foxgloves BOTANICAL NAME: Digitalis purpurea HARDINESS RATING: H7 PREFERRED SUNLIGHT: FULL SUN / PART SHADE FLOWERING SEASON: SUMMER 20) Weigela BOTANICAL NAME: WEIGELA HARDINESS RATING: H6 PREFERRED SUNLIGHT: ANY FLOWERING SEASON: SPRING / SUMMER Tips For Growing Under Trees The first factor which will influence your choice is whether the tree in question is evergreen, coniferous or deciduous. The former will pose particular problems for planting beneath it, since the year-round coverage of the foliage means that the ground directly below is likely to suffer from very little sunlight exposure and excessively dry soil conditions. What’s more, the proliferation of needles and other debris which often accumulates can make satisfactory growth of any plant – including grasses – a difficult endeavour. But while it might be difficult, it’s certainly not impossible. In that type of situation, it’s advisable to trim back the lower branches of the tree to ensure that some sun can filter through. This is known as crown lifting. You should also mulch the area beneath the tree with organic matter, leaving a buffer of around three feet between the trunk and your plants to ensure that its root system doesn’t interfere with their growth and vice versa. These precautions are sensible for any tree, regardless of whether it loses its leaves in winter or not. Having said all that, there’s no reason to approach the cultivation of plants underneath trees with trepidation, since there is a wide array of varieties that can survive and even thrive in such conditions. You might also want to check out our best ferns for dry shade – many of which will grow well under the shade of a tree. References 1. Breedlove, D., Berry, P., & Raven, P. (1982). The Mexican and Central American Species of Fuchsia (Onagraceae). Annals of the Missouri Botanical Garden. Retrieved March 22, 2023, from https://www.jstor.org/stable/2398791
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Olives Respond Very Well To Pruning: Encourage Fruiting And Keep Your Plant In Check
IN THIS GUIDE When To Prune Olive Trees Do They Need To Be Pruned? Maintenance Pruning Pruning For Fruit Pruning To Restrict Size & Preserve Form Olive trees are beautiful Mediterranean trees that can look wonderful in a sheltered, warm spot here in the UK, but learning how to prune them correctly is important. When and how to prune your olive tree and the reasons for doing so, will vary depending on why you are growing your olive tree, where you are growing it and what precisely you are aiming to achieve. Olive trees can be beautiful trees to grow in a warm, Mediterranean-style garden. Understanding how to care for your olive tree correctly is important and that includes understanding how and when to prune the tree. When To Prune Olive Trees First of all, whenever pruning an olive tree (for whatever purpose and with whatever goal) it is important to choose the right time for the job, as Paul Smith from The Norfolk Olive Tree Company explains: “Like most evergreen trees, Olives respond very well to pruning. In fact, the more you prune, the happier they’ll grow”. “However, is best to prune your Olive Tree after the last of the winter frost, from March onwards, and before the first autumn frosts, which is usually between late October and early November”. Typically, you will prune an olive tree between late spring and the end of summer. It is important not to prune your olive during the winter, as this can make the tree more vulnerable to infection with disease. Always prune over the warmer part of the year to reduce the chances of disease taking hold. Unfortunately, olive trees can be rather prone to a number of diseases, especially in a cooler climate. Pruning incorrectly and at the wrong times can make it more likely that one will take hold. Some only slightly impact the appearance of the tree, but some diseases could actually kill your olive tree outright. Do They Need To Be Pruned? Though pruning can often be a good idea, olive trees are relatively slow-growing and should not need a lot of pruning at all in most scenarios. However, it is important to note that it is good practice (with an ornamental olive tree) to remove any dead, damaged or diseased materials as part of general care and maintenance. If you are trying to grow an olive for its fruits, then the pruning considerations are somewhat different. This is not always very easy in the UK, as the trees will typically only fruit in the mildest and warmest of UK gardens. And even when the fruits do set successfully, you will still have to harvest the fruits before the first frosts and cure them before they are used. Curing is essential if you want olives that taste like those you can buy in the shops. Bear in mind that these trees thrive in the hot, long growing season of the Mediterranean and so work will be required to obtain an edible yield in our climate, with our much shorter growing season. Another consideration is that here in the UK, olive trees are often grown in containers, and some pruning may be required for container-grown trees to keep their size in check and to stop them from outgrowing a container. In short, therefore, you might wish to prune olive trees: For simple maintenance. To encourage fruiting and promote new fruit production. To keep the size and shape of the tree in check. However, while olive trees can respond well to pruning, it is important not to go overboard. Prune too excessively and the tree may put forth numerous water shoots (not fruiting growth). This is not ideal if you are trying to produce fruit, of course. It can also detrimentally affect the overall appearance of your olive tree. Olives should usually be pruned quite lightly in order to preserve a more natural appearance, as Paul Smith advocates: “Light and more light is the overwhelming principle of pruning. If you prune back your Olive Tree hard, this will result in a dense growth, whilst a light, formative prune will give your tree a natural shape. “Also, letting the light into the tree improves fruit production and letting in the light also keeps the tree under control. “If the tree is dark and dense, branches will race up and out to find more light, making the tree leggy”. Maintenance Pruning Usually, if an olive tree is growing in the ground, light, maintenance pruning is all that will be required. Simply remove any branches which are causing damage by rubbing on one another, and any which have been damaged over the winter months in late spring or early summer. At the same time, you may also prune some branches at the centre of the canopy to let more light in to new growth, and remove a side branch or two to maintain a pleasing shape. But do not overdo it – less is usually more when it comes to maintenance pruning on an olive tree that is grown for ornamental reasons and not for its fruit. Dan Ori recommends: “If you are not worried about impacting the fruiting, young olives can be trained and trimmed into attractive loose lollypop shapes; you will often see pairs of lollypop olives framing the doorways of opulent city homes.” Pruning For Fruit When pruning an olive tree for fruit, Paul Smith explains that one of the most important things to remember is that olives fruit only at the tips of the previous year’s growth. “The olive tree produces fruit mainly at the periphery and top of the canopy. This is because these parts of the tree are fully exposed to sunlight and in turn improves fertility. “When pruning for fruiting purposes, you should focus on the removal of any part that shades other younger parts of the tree”. Pruning too zealously can prevent fruiting. However, not pruning at all can lead, over time, to a tree with too much older wood, which may also restrict new growth and prevent light from reaching and ripening any fruits that do form on the last year’s branches. It is a good idea, therefore, to prune out sections of old wood each year to allow some newer fruiting growth to form. It is also recommended to thin fruits that form to no more than 3-4 for each 30cm of branch. This should help ensure that the olives ripen successfully and will not drop off the tree prematurely before harvesting time. “I recommend growing an olive in a pot against a sheltered sunny brick wall for the best chance of ripened olives,” says Dan Ori, a Member of the Arboricultural Association. Pruning To Restrict Size & Preserve Form Pruning to restrict size is not usually a concern when these slow-growing trees are grown in the ground. But when they are grown in containers, you may need to do some additional pruning so they do not outgrow their pot. In addition to the general maintenance pruning in the late spring or early summer, a container-grown olive may also require additional pruning in summer to restrict their size. Paul Smith suggests that if your potted Olive Tree is not thriving in its pot, you can reduce the canopy size of your tree by up to one-third to keep its size in check and restore the plant’s health. When olive trees in containers grown to around 1.5m tall, it is also often a good idea to prune to preserve or create a pleasing form. Choose a few of the strongest and best-placed branches and keep these, but get rid of other shoots. It should also be noted that you can take pruned branches in summer and use these as semi-ripe cuttings to propagate new olive trees from the parent plant. You might also pinch out the growing tips to encourage branching and a bushier canopy. Olive trees are not the easiest trees to care for and grow successfully in a UK garden, but pruning them is rarely a hugely complex business.
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Why Growing Magnolias In Pots Allows You To Easily Meet Their pH Requirements
IN THIS GUIDE Can Magnolia Trees Be Grown In Pots? Potted Magnolia Varieties Positioning Potted Magnolia Choosing Containers For Magnolia Potting Mix For Magnolia Planting Magnolia In Pots Caring For Potted Magnolia You might think of Magnolias as a plant for larger gardens, but some can be grown in pots. In this article, we will talk about which magnolias to grow in pots in a container garden, and the choices you will have to make to keep them healthy and happy. Can Magnolia Trees Be Grown In Pots? In short – yes! If you grow magnolia trees in the ground, you will obviously be able to choose from a wider variety of plants, and they will take a lot less work. Container gardens are generally higher maintenance for the gardener. However, there is one very good reason why you might wish to grow Magnolia in containers, and that is because of their pH requirements. Magnolia trees like neutral or acidic soil conditions. While some can cope with more alkaline conditions, if you have very alkaline soil, it is often best to grow Magnolias in containers rather than fighting to amend the pH and grow them in the ground. Fortunately, magnolia trees have rather shallow roots, which can make them a good candidate for growing in larger containers. Some types have fragrant flowers which makes them great for positioning in pots close to a seating area or outdoor leisure space. Potted Magnolia Varieties M. stellata ‘Rosea’ Magnolia trees can be full-sized trees or larger shrubs. If you plan on growing Magnolia in a container then it is important to choose the right variety. Those with smaller forms and less vigorous growth habits are generally easier to grow in pots. Some options to consider which can be good for container gardening include: M. ‘George Henry Kern’ M. ‘Susan’ M. stellata ‘Jane Platt’ M. stellata ‘King Rose’ M. stellata ‘Royal Star’ M. stellata ‘Rosea’ M. denudata ‘Sunrise’ M. denudata ‘Yellow River’ M. x loebneri ‘Mag’s Pirouette’ M. x loebneri ‘Merrill’ M. x loebneri ‘Merill’ Make sure that you understand how large the Magnolia you are considering will eventually grow, and remember that while some Magnolias can be grown in containers, not all can. Even those which are good for container growing will need a sizeable pot and the right conditions to thrive. Positioning Potted Magnolia Magnolias, whether grown in the ground in a garden or in pots, will require a site that is as sunny and sheltered as possible. Magnolias are actually usually pretty hardy in the UK, however, the flowers of magnolias can easily be damaged by early spring frosts. Choosing Containers For Magnolia Magnolias are usually purchased as pot-grown trees, though they can come in a range of containers of different sizes. It is best to repot your Magnolia as soon as it arrives into larger, heavy containers which can support the weight of a small tree or shrub and which will not tip over easily. You can purchase containers, but there is also a range of reclaimed items you could consider. Remember to choose a container that will not dry out too quickly during the summer months. Inadequate water over the summer is one of the common reasons why a magnolia might not flower as expected. Remember that a black or dark-coloured container will heat up and dry out more quickly. The material from which a container is made is also important – glazed pots are better than terracotta for water retention, for example. It is also important to make sure that your container has drainage holes and allows for good drainage too. Magnolia trees grow root systems very quickly and intricately, so it is important to choose a container that will suit the ultimate size of your tree. Look at the girth of the trunk to get an idea of how wide the container needs to be. A Magnolia with a trunk that is 2cm wide, you will need a container at least 60cm wide and 60cm tall. For each centimetre around the diameter of the trunk, the container should be 30cm wider and taller. So if a mature magnolia tree trunk is 5cm around, it will need a container or planter 1.5m wide and 1.5m tall. Larger containers will be needed to grow Magnolia to maturity in pots. Potting Mix For Magnolia As mentioned above, Magnolias can thrive in neutral or acidic soils. Many magnolias will grow perfectly well in a general multi-purpose compost with added John Innes (or a homemade equivalent). However, certain varieties will thrive in more acidic conditions and so it can sometimes be beneficial to fill your pots for Magnolia with an ericaceous potting mix. Whichever potting mix you choose, make sure it is light and free-draining, yet moisture retentive, to keep your magnolia tree as healthy and happy as possible. Planting Magnolia In Pots When you are planting a magnolia into its new pot or container, it is important to take care not to damage the root system as you do so. As is usual with trees and shrubs, it is important to make sure that you bury the magnolia to the same level that it was in its previous pot. Make sure the graft point is not below the surface of the growing medium. After planting, water well around the base of the plant, and top the growing medium in the container with a leaf mould or another good quality organic mulch. This will help to retain water in your pot and stop weeds from growing up as much around the base of your tree. Of course, it will also help add fertility, providing nutrients as the materials decompose slowly over time. Caring For Potted Magnolia Watering Remember that a magnolia grown in a container will need to be watered more frequently in dry weather than one which is grown in the ground. Keep the soil moist throughout the summer months to keep magnolias healthy and flowering well. “Ideally water in the morning when plants begin to use it, although evenings are also okay,” advises Colin Skelly, an RHS Master of Horticulture. “To ensure that water is available to the plant throughout the pot soil, watering thoroughly less frequently is better than frequently but less thoroughly.” Feeding Magnolias grown in the ground will typically require only mulch, and will not need additional feeding. When grown in pots, however, some additional liquid feed may be helpful. Feeding magnolias grown in containers in early spring with a high phosphorus and potassium liquid feed can promote healthy growth and encourage more abundant flowering. Pruning Magnolias should only be pruned lightly, and after flowering. Remove any branches which are dead, damaged or diseased and any which are crossed and rubbing against one another. You can also prune to restrict size somewhat, but should be circumspect as these trees do not like or respond well to hard pruning. If you prune too much, flowering may be reduced or cease the following year. As long as you choose the right magnolias, place them in the right containers, with the right potting mix, in the right location, growing magnolia in pots is not too much of a challenge. Just make sure you do not let them dry out. Replenish mulch to add fertility each year, and your magnolia tree should be content in your container garden for many years to come.
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7 Reasons Your Conifers Are Turning Brown With Feeding Advice From Peter Lickorish
IN THIS GUIDE Why Your Conifer Is Turning Brown 1) Not Enough Water 2) The Wrong Compost 3) Not Enough Space 4) Choose The Right Spot 5) Make Sure There’s Drainage 6) Not Enough Nutrients 7) Don’t Prune Too Hard! Enjoying Your Evergreens Conifers turning brown is a surprisingly common problem for gardeners in the UK. And whenever bright evergreen begins to fade into a sickly brown, it is indicative of a wider issue with the conditions your conifer is growing in. At first only a few needles might change colour, but others follow suit until eventually, the healthy hue disappears completely. And it’s usually one of the same handful of problems that interfere with their ability to do so. Why Your Conifer Is Turning Brown When you think about it, plants need very little to thrive. It’s just a case of getting the right soil, the right levels of water and sunlight, enough space for the roots, and a careful eye to ensure that any issues are nipped in the bud. While different varieties have varying needs, common problems with conifers tend to centre around the same things, so let’s take a look at the various issues you may encounter. 1) Not Enough Water These trees are used to growing in environments where the weather may not be particularly pleasant. They can handle melting snowdrifts and all sorts of wetness. Sitting in the small amount of dry soil that fits in a container then, probably isn’t ideal. If you’re growing a conifer take care to keep it very well watered. More so than you probably expect: sometimes they require watering twice in the same day during particularly hot spells. And if you see water seeping out from the bottom of the pot, this can be a good indication that the roots are taking up too much space in the soil or that you’re using the wrong compost. In the first instance, there’s just not enough soil available to soak up the moisture required to keep the plant alive. And in the second instance, the soil is unable to hold enough moisture regardless of whether there’s enough of it. 2) The Wrong Compost Conifers need compost that retains moisture, and regular potting compost won’t do the trick, unfortunately. A soil-based mix with added material like composted leaf bark or leaf mould will help to hold more moisture, and to let air circulate around the roots. Ask in your local garden centre if you need advice on the specific compost mix for the conifer(s) you’re looking to grow. Different types have different requirements, and it’s important to get this right. 3) Not Enough Space The reality is that conifers will do best when they’re grown in the ground. These are proud and hardy trees that can hold their own against the elements, and a life spent in a small pot isn’t really ideal. If you buy a potted conifer, consider planting it out into the ground after a year or so. This, combined with vigilant watering, should give it the best shot at thriving. If you’re wondering why this becomes problematic, think about the roots of the conifer. As the tree grows so too do its roots, and in a small pot they’re quickly going to run out of space. As the ratio of roots to soil changes, it gets exponentially harder for the conifer to get the nutrients it requires. Needles turning brown and dropping off is a desperate attempt by your plant to shepherd its resources but, unless you take action, this is unlikely to be enough to save it. 4) Choose The Right Spot If you do decide to move your conifer outside, try to find a sheltered spot that gets full sun or partial shade. Shelter is important because strong winds can scorch the plant, turning exposed needles brown and causing damage. 5) Make Sure There’s Drainage Wherever you grow your plant, make sure there’s suitable drainage to allow any water that’s not absorbed to seep out. In a pot this means drainage holes, and maybe even a layer of gravel between the bottom of the container and the soil. In the ground, this means suitable irrigation. You’ve probably noticed that we advise watering often and using a compost that can retain moisture, while also advising you to ensure there’s plenty of drainage for excess water. This is because with conifers, it’s notoriously tricky to get the right amount of water. While they’re hardy, they’re also fussy, and once things start to go south it can be hard to get them back on track. 6) Not Enough Nutrients Nutrition is crucial in keeping plants alive and well. We advise feeding your conifers in late winter, then mulching the top of the soil. “Make sure that the bottom of the pot is ridged or the pot is raised off the ground to let the holes actually drain,” shares Master Horticulturist Peter Lickorish. This will top up their nutrients and hopefully encourage stronger growth. You can buy special feeds for conifer plants, or they’ll respond well to 10-10-10 or 16-8-8 mixes. Applying feed once a year will be enough to keep these trees suitably nourished: resist the temptation to over-feed as this can disrupt their delicate balance. “In pots, feeding more regularly is important; nettle tea can be watered onto the compost every few weeks between spring and late summer,” Peter adds. 7) Don’t Prune Too Hard! Many gardeners get a little over-enthusiastic when pruning their conifers, out of a desire to keep them looking neat and trimmed. Unfortunately however, pruning too aggressively can shock the plant and cause damage. And because few conifers regrow from old wood, it can take a permanent toll, as Peter shares. “Most conifers do not have dormant buds, so pruning back past the green growth leaves no buds to re-sprout. Hence, the infamous dead patch in a conifer. “There is an exception – yew is particularly good at regenerating from a hard prune if carried out in summer. That’s one reason why I find yew, Taxus baccata, to be among the best conifers for hedging. “Pruning too early can cause new growth to get frosted and, you guessed it, turn brown.” When it’s time to prune, be gentle. Only take off a small amount, and do this only in April through August. It’s far preferable to take off too little then rectify later on with another gentle prune, rather than to hack off so much that you cause irreversible damage to the plant! Enjoying Your Evergreens With the right care it’s possible to avoid this fate Grown with the care and attention they require, conifers are beautiful and rewarding plants to have in your garden. They’re big, bold, and vibrant, holding their colour year-round and providing a reminder in the lean months that Mother Nature will hold court again shortly. While it can feel like a bit of a balancing act getting the conditions right for your fledgling conifer, once you get a feel for it and your plant begins to get established, you should find things easier. Just remember that they’re thirstier than you might expect, that good moisture retention and good drainage are both required, and the over-zealous pruning will cause way more harm than good. And whether you decide to keep a conifer in a small container on your desk, a large container on your patio, or encircled in your lawn, the steps in this guide should hopefully help you to keep it alive and well for a long time to come.
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Only Prune Maples 'If You Want To Form The Tree In A Precise Shape' Says This Expert
IN THIS GUIDE Why Prune Acer Trees? When To Prune Acers How To Prune Acers Formative Pruning Pruning For Size Restriction Pruning For Shape & Aesthetics Pruning For General Maintenance & Plant Health Pollarding & Coppicing With Acers large and small it is usually best to keep pruning to a minimum but there will be some times when pruning may be required or desired. Acers, both larger maples and small Japanese trees, often perform best when more or less left to their own devices. Pruning excessively can often weaken the trees, and is often unnecessary. However, there are certain occasions when pruning can be desirable. Read on to learn why you might wish to prune Acers, when and how to do so. Why Prune Acer Trees? Acer palmatum “Maples do not require pruning unless you want to form the tree in a precise shape,” says Agustin Coello-Vera from The Maple Society. Small Japanese maples are usually best when left to grow naturally, and pruning should generally be kept to a minimum. Larger maples may also be left largely to their own devices. However, there are certain reasons to prune and all Acers can be lightly pruned to achieve certain results. Acers might be pruned: Formatively – to form their initial pleasing shape during early stages of growth. To restrict their size. To maintain a pleasing and aesthetic shape and form. For general maintenance and to preserve the ongoing health of the trees. When To Prune Acers Acers of all types should almost always be pruned during the dormant period, between November and March. When pruned during the growing season, Acers can bleed sap from pruning cuts, which can weaken or damage the trees. However, while winter pruning is best, you should also generally avoid pruning when temperatures are below zero. “Small pruning can be done any time, but major pruning is best done from late summer to late winter before the sap starts to rise,” states Agustin. Pruning in winter after leaf fall also makes it easier for you to see the structure of your trees. The only exception to this is when maples such as field maples are being used as part of a hedgerow. For hedgerows, maples are sometimes pruned not only during the winter, but also in late spring and sometimes also in September to keep them neat and in check. How To Prune Acers Formative Pruning Larger maples are typically purchased as 2-3 year old trees. These will likely have already undergone a process of formative pruning to create well-shaped trees. Formative pruning is not something most gardeners will have to consider. However, if you are growing your maples from seed, or younger saplings or ‘maidens’ then some pruning may be required, largely on aesthetic grounds, to create a clear trunk and a well-spaced, nicely shaped canopy of branches. Pruning For Size Restriction Another reason to prune Acers is to restrict their size – slower-growing and small Japanese maples will not typically have to be pruned for this reason. They do not respond well to extensive pruning and should always be chosen for their height and spread. Field maple hedge Make sure you choose a Japanese maple which is suited to the position in which you wish it to grow. But larger maples may be pruned to make them more suitable for growth in a smaller garden. On rare occasions, you may wish to prune even smaller trees to reduce size and width. To do so: Simply trace longer branches back to a side branch and prune them out at this point. Young maple trees can be pruned in their first winter to create a short trunk and a more shrubby growth habit. Prune around 50cm high, just above two pairs of strong shoots. Shorten these shoots to around 1/3 of their length to encourage them to branch in the spring. The following winter, shorten the main shoots a little. To restrict the size of a mature large maple, it is also possible to carefully remove up to 1/3 of the canopy, though extensive renovation pruning is best undertaken over a number of years. With smaller Japanese maple you should never remove more than around 20% of the canopy, ideally a lot less – and should not take more than around a quarter of any one branch. Where Acers such as field maples are being grown as part of a hedgerow, you may prune both in the winter, and in the late spring, taking down the height and reducing the width as required. In certain cases, another pruning may be necessary in September to keep the hedgerow neat and tidy. Pruning For Shape & Aesthetics Japanese maples will usually be pleasantly shaped when purchased, and extensive pruning for shape and aesthetics will rarely be required. If your Acer creates a strong vertical shoot, however, which spoils the balance and appearance of the tree, you can prune this back to a side branch. A mountain maple bonsai in winter Some gardeners may also choose to prune Acers to achieve certain aesthetic effects – as in bonsai cultivation and other forms of decorative pruning or topiary. Work with the natural shape of the tree to create visually pleasing forms, removing or shortening certain branches as desired, but take care not to overdo it. As mentioned above, maples will often look best when allowed to grow in a more natural way. Pruning For General Maintenance & Plant Health If trees are growing naturally, and are not pruned for size, shape or aesthetics, then you will usually only stick to general, occasional maintenance pruning. This involves simply checking over your Acers carefully and cutting out any branches which are dead, damaged or diseased. You may also find tips damaged by cold weather which can be pruned off. Other than removing any damaged material, you should not need to do much Acer pruning at all. However, on mature maples, it may sometimes also be helpful to remove any branches which are crossing or overly congested to open up the centre of the canopy to improve the health of the tree. Whenever you are pruning Acers, you should always aim to avoid leaving stubs, since these can be prone to decay and die back. Always prune back to a well-spaced side branch wherever possible. Remember, pruning Acers should be kept to a minimum, and should almost always only be undertaken during the dormant period. Maples are a great low-maintenance option for your garden, and pruning them will not take up much of your time – if it takes up any time at all. Pollarding & Coppicing “Two other types of pruning you may see in Acers are pollarding and coppicing, although it would be unlikely in Japanese maples,” advises RHS Master of Horticulture Dan Ori. Pollarding and coppicing in the winter can be performed for a variety of reasons, explains Dan. “The traditional reason is timber production (in a garden setting this is normally for firewood). “Alternative reasons are [typically] because the tree is too big for the space and past the point where a crown reduction up to 30% would be enough, to create multiple stems from the base (coppicing) or a canopy at a desired height (pollarding), or to produce fresh new colourful stems or leaf every 1-3 years. because the tree is too big for the space and past the point where a crown reduction up to 30% would be enough, to create multiple stems from the base (coppicing) or a canopy at a desired height (pollarding), or to produce fresh new colourful stems or leaf every 1-3 years. “Cultivars of Acer pseudoplatanus and Acer negundo are commonly pollarded to produce fresh golden or variegated leaves.”
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Horticulturists Explain Why Ericaceous Compost Is A Must For Acidic-Loving Acers
IN THIS GUIDE What Is Ericaceous Compost? What Are Acers? Do You Always Need To Use Ericaceous Compost For Acers? Deciding Where To Grow Acers Understanding Your Soil Type Choosing A Potting Mix For Acers DIY Acer Potting Mix References Acers are trees that like acidic pH levels, so using ericaceous compost can sometimes help keep them healthy and give them the growing conditions they need. However, while most Acers do enjoy acidic conditions, many are surprisingly tolerant of neutral or even alkaline soils, as long as their roots receive sufficient moisture and oxygen. When growing in containers, using ericaceous compost for Acers can be optimal. However, when growing in the ground in your garden, special ericaceous compost may not actually be required. What Is Ericaceous Compost? Ericaceous compost is a growing medium that has a low pH, which makes it suitable for acid-loving plants. Compost is made up of decomposed or partially decomposed organic matter. Sometimes, the term is also used to refer to potting mixes, or growing media. But technically, potting mixes are made up of compost plus other materials. Both ericaceous composts and ericaceous potting mixes can be useful when growing Acers and other acid-loving plants in your garden. Though it is important to remember that composts and potting mixes are not exactly the same thing. An ericaceous compost might be used as a mulch to improve the soil and add fertility around acid-loving plants grown in the ground. It might also be used to top up containers when repotting Acers or other plants which enjoy acidic conditions. It will also often be used alongside a loam-based potting mix or growing medium to fill the containers in which Acers will be grown. What Are Acers? Acers belong to a diverse genus of trees which includes large trees (maples, and the sycamore), and small trees which are really more like shrubs (including the ever-popular Japanese Acers: Acer palmatum). Acer palmatum A. palmatum are attractive small trees that are perfect for small gardens and container growing. There is great variety in the leaf colour and foliage of these Acers, and they are highly prized for their foliage colours and autumn hues. Do You Always Need To Use Ericaceous Compost For Acers? Acer palmatum, and other Japanese maples, when grown in your garden, may not require soil amendment to alter pH. If you have a soil which is reasonably moist yet free-draining and not compacted, these trees should endure even where the conditions are neutral or even slightly alkaline in pH. Many refer to the excellent Westonbirt arboretum as proof that Acers can thrive in any conditions – where many Acers thrive in the Cotswolds’ limestone soil.1 However the truth is not quite so straightforward, as experienced Horticulturist Dan Ori explains: “People often quote the Acers at Westonbirt arboretum as proving that they can grow on non-acid soils, but firstly not all are Japanese maples, and secondly there is a difference between tolerating with lots of help and years to adapt, rather than thriving from the moment it is planted. “Japanese Acers will tolerate most soil types but only really do well in acidic moist but not wet soil.”2 So, while these trees are not as sensitive to soil pH as many other ericaceous plants, when growing Acers in containers, using ericaceous compost will likely yield the best results. Deciding Where To Grow Acers Japanese maple shrub growing in a container If you have particularly alkaline soil, then you will likely do best if you grow Acers in containers. Otherwise, you can generally place them in the ground in your garden. Think about all the different environmental factors when choosing the best location – not just the soil pH. They can thrive in full sun, dappled shade or partial shade. Typically, they will do best in a sheltered spot, though most cultivars can cope with some wind exposure. These trees are much less fussy than a lot of people think. If you have a heavy clay soil, make sure you amend it with plenty of organic matter to improve soil structure and drainage before you plant your Acer. Understanding Your Soil Type In order to decide whether you need to grow Acers in containers or you can grow in the ground, your first step should be to determine your soil pH. You can get clues about the soil in your garden from the plants already growing there and their needs, and get a rough idea about whether it is acidic, neutral or alkaline from simple home tests with vinegar and bicarbonate of soda. But to determine the pH, you will need to get a soil testing kit. If your soil pH is much above 7, it is alkaline and it may be better to grow Acers and other ericaceous plants, if you wish to grow them, in containers. Learn more about soil testing in this guide. Choosing A Potting Mix For Acers Fine compost If you decide to grow Acers in containers – for whatever reason – it is important to choose a growing medium to optimise conditions and ensure that the small trees remain as healthy as possible. A 50-50 mix of ericaceous compost and John Innes No 3 is generally thought to be the best option. John Innes No. 3 is a nutrient-rich loam-based potting mix that is used to establish shrubs and trees and plants which will be kept in their containers for a long period of time. DIY Acer Potting Mix If you want to make a similar potting mix yourself, it is made up of: 7 parts sterilised loam 3 parts peat substitute (coir, leaf mould, woody compost) 2 parts loose sand Mix these ingredients at a ratio of 1:1 with an ericaceous compost which you buy (or make using more acidic organic matter, which can yield more varied results). Acidic materials for an ericaceous compost include leaves, especially oak, pine needles, citrus, onions, sawdust from fresh-cut wood. Note that pH will return to a more neutral level over time. Sulphur is sometimes added to containers for ericaceous plants to provide more acidic conditions over time. However, since Acers are not usually fussy, this is not essential in their case. To summarise – while this mix is said to be optimal, Japanese maples, or Acers will also usually grow fine in a typical loam-based compost. “Unlike most acid-loving plants, Japanese maples are more tolerant of higher pH – often surviving in alkaline soils,” says Dan Ori. “But if you have alkaline soil then it is advised to grow them in ericaceous compost or choose an alternative Acer that thrives in lime/alkaline soil like Acer campestre ‘Nanum’.” References 1. Ballard, M. (n.d.). Westonbirt, The National Arboretum. Westonbirt Forest Design Plan. Retrieved March 9, 2023, from https://www.forestryengland.uk/sites/default/files/documents/Westonbirt%20Forest%20%28Arboretum%29%20Design%20Plan%202021-2030-merged-compressed_0.pdf 2. Hansen, S. M. (n.d.). Maples in the Landscape. Utah State University. https://digitalcommons.usu.edu/extension_curall/2188/
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