Horticulture Magazine

6 Types Of Houseplant Bugs & What To Do With Them

landbirds and aphids on a plant

Plenty of pests can wreak havoc on your carefully-tended houseplants.

Such abuse is dispiriting and can cause untold, permanent damage to your plants but, thankfully, there are steps you can follow to remove and, more importantly, prevent such pests.

closeup of green aphids on a plant
Your beautiful houseplant is their tasty supper

In this guide we’ll look at the most common houseplant bugs you’re likely to come across in the UK, steps to prevent them taking hold, and steps to remove infestations should they occur.

Types of UK houseplant bugs

There are several main contenders – a variety of minibeasts that threaten UK houseplants with their presence. You may notice slugs and snails missing from our list. This is deliberate, as often these slimy fellows will stay outside. If your plants are being ravaged by slugs and snails, take a look at this guide from the RHS.

1. Thrips

What are they? Small insects that suck sap from the leaves of plants, leaving damage in their wake.

What do they look like? Winged insects about 2mm long, with light hair on the wings. Likely colours include pale yellow, brown, or black.

Signs of their presence: You’ll notice dull, discoloured leaves with black spots. White flecks on flowers can also indicate presence.

2. Leafminers

What are they? A family of pests that burrow into leaves to get at the nutrients inside. Their presence looks worse than it is.

What do they look like? Because there are so many pests in this category, appearance varies. Also, the damage they cause is a better diagnostic than the aesthetic qualities of the bugs themselves.

Signs of their presence: Tunnel-like burrows on leaves, often brown, and possibly with black excrement left behind.

3. Beetles

What are they? Another vast family of insects containing hundreds of thousands of distinct varieties – some of whom like to live on and eat houseplants.

What do they look like? Beetles have hard wing cases, a line down the middle, and antennae, but there’s so much variation between species that there’s no fixed answer for this question.

Signs of their presence: Beetles will be visible to the naked eye, and will likely create holes in the leaves they feed on.

4. Whiteflies

What are they? Sap-sucking flies that damage plants through stealing their nutrients and leaving damaging excrement.

What do they look like? Small and white, with translucent wings. Often you’ll see them in large groups.

Signs of their presence: Easily visible clusters of flies, evidence of sticky and sugary excrement on leaves, general poor leaf health.

5. Spider mites

What are they? One of many mites feed on sap sucked from leaves. Over-feeding can cause leaf damage and death, if left unchecked.

What do they look like? Small bugs, about 1mm in length, translucent bodies whose colour depends on the variety.

Signs of their presence: Mottled leaves, white cast skins or egg shells visible, silk web on plants, and discoloured leaves.

6. Aphids

What are they? Yet another sap-sucking pest whose colonies damage plants they decide to take up residence upon.

What do they look like? Small and greeny-yellow, ranging in size from 1mm to just shy of a centimetre. There are many varieties, meaning exact size and colouration can vary.

Signs of their presence: Visible clusters of insects, stunted growth, mouldy leaves, cast skins, and sometimes ants are an indication of aphids nearby (the two share a symbiotic relationship).

Prevention is the best medicine

With most things in life, taking preventative measures is often more effective and painless than waiting until things hit a crisis point to take action. The same is true with preventing houseplant bugs.

There are a few simple steps you can take to reduce the risk of infestation. Where possible, incorporate these into your regular plant-care routine. Hopefully pests will be discouraged and will turn their attention elsewhere, leaving your plants to thrive.

Establish a perimeter

Pests are often brought in with plants, but they can find their own way in, too. If you have windows and doors open regularly to let fresh air in, try to use screens and barriers to keep pests out.

a fly sat on a window screen
What can’t get in can’t hurt you

Listen to your plants’ needs

Pests are most likely to take hold when your plant is vulnerable. Giving them the right amount of sunlight and water, and the right conditions to thrive, will help your plant to grow big and strong, thereby lowering the risk of infestation.

Inspect newcomers

This point applies to plants you’ve just bought from a garden centre, and to those you’re bringing in from a summer spent outdoors. Both have the potential to bring pests from their old home and into yours.

With plants that are new to you, check the entire plant for signs of pests. Give the leaves, stalks, and flowers a once over. If you find anything, keep the plant outside or in quarantine until you’ve taken eliminatory steps.

For plants you’re bringing indoors after a summer outing, you’ll need to check the soil too. Opportunist pests can take root (pardon the pun) and sneak indoors to wreak havoc.

Here’s what you’re looking for during an inspection –

  • Pests hanging out on the bottom of leaves. They may be quite small, so a magnifying glass is helpful in spotting them early.
  • Blemishes or mottling on leaves.
  • Holes in leaves.

Quarantine

Keeping new plants away from others for a few weeks is a surefire way to ensure there are no pests. Sometimes an inspection like the one in the previous step will miss small or particularly well-hidden pests: Quarantine is a way to force them to show themselves before any other plants can be affected.

Water the soil, not the plant

This ties back to our second point of listening to your plants’ needs. Sometimes when watering, people liberally apply water to the plant itself with the hope that it’ll trickle down into the soil. Where possible, avoid this. Especially indoors, where there’s less likely to be enough sunlight for the water to evaporate away.

Moist, soggy leaves are an inviting prospect for pests, and represent an easily avoidable vulnerability. Water the soil directly.

Use store-bought soil

If you’re repotting, use bought compost rather than soil scooped up from your garden. This greatly reduces the chance of bringing in pests from tainted soil, and has the bonus benefit of ensuring more reliable nourishment for your plant.

Getting rid of plant pests

Sometimes, the best preventative measures just don’t work. Bugs are perseverant and tenacious, and they’ll probe for gaps in your defences no matter how well-laid they are. When this happens, you have to ramp up the attack.

Here’s what to do.

Make a decision

How attached are you to your infected plant? Although it may seem harsh, getting rid of plants you’re not overly attached to can often be the easiest way to resolve an infestation.

If the thought of throwing your plant out fills you with rage, that’s a good indication that persevering with the following steps is the best course of action. If it doesn’t, consider scrapping the plant and moving on.

Isolate!

As soon as you notice pests on a houseplant and you decide to save it, isolate the plant. Move it away from your other plants and keep them separate until you’re confident you’ve removed the problem completely.

This step will prevent pests spreading themselves enthusiastically around all of your plants.

Be persistent

Sadly, getting rid of pests can be quite a long haul, as they’re unlikely to give up their ill-gotten gains without a fight. Steel yourself and know that they will be gone eventually.

Evaluate the damage

When pests take hold, they won’t necessarily infect the whole plant straight away. If it’s only a partial infestation, you have a couple of options –

  • If some leaves are infected, remove and destroy them. Keep an eye on the plant for a couple of weeks afterward to see whether any lingering individuals establish another infestation: If so, repeat the process.
  • If the roots are infected, take a cutting and use it to establish a new plant. Grow the new plant away from the infected one and away from your other plants, until you’re confident it’s clean.

Pick off any pests that are big enough

Although it’s icky, manually removing pests is an effective way to reduce their hold on your houseplant. Pinch them gently and remove if they’re big enough. If not, use a cotton bud dipped in disinfectant, or tweezers, or something similarly able to scrape them away.

Ideally you’ll want to squash the pests and throw them in the bin.

child with a magnifying glass looking closely at a plant
A magnifying glass can help with this job

Spray your plant with non-pesticides

Spraying with water can help with physically removing pests, and mixing some insecticidal soap into the water can boost effectiveness. These soaps are available from gardening stores, and are specially formulated to discourage insects.

Spray your plant with pesticides

If the previous steps haven’t helped to alleviate your infestation, more drastic measures must be taken. Pesticides are potent chemicals designed to kill and remove pests, but beware: Their potency increases the risk of damage to your houseplant and to yourself. Always follow instructions and use pesticides carefully.

There are various pesticides available, each intended for use with specific types of pest. For this reason we can’t include usage directions, but each product will include detailed instructions on the packaging. Make sure to follow these.

The best defence is a good defence

Remember, preventative measures are almost certainly more effective at remedial ones. Keeping your plants in good condition, respecting their needs, and taking steps to reduce the risk of infestation should hold pests at bay.

If they do find their way in, whether through a window, on a new plant, or hidden deep in the soil, pests can be contained. While it’s frustrating and dispiriting, all that’s required is perseverance and the right steps taken at the right time.

We hope our guide to the types of UK houseplant bugs and what to do about them has been useful. If you’re reading to learn how to remove an existing pest problem, we wish you all the best in doing so.

© 2021 TKO DIGITAL LTD | Registered in England and Wales No. 10866260 | This website uses cookies.