How to get rid of garden pests

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It's important to remember that all pests are part of the garden ecosystem and food chain, and that many are an important source of food for birds and other wildlife. For example, house sparrows feed aphids to their chicks, while blue tits and great tits feed caterpillars to their young.

Sometimes, however, you need to control garden pests yourself. But what's the best way to deter them? And are there organic pest control options? We’ve set out the most common garden pests and ways to deal with them, below.

How to get rid of slugs and snails

Slugs and snails are most gardeners’ enemy number one. The tender leaves of seedlings and fresh new growth on established garden plants are magnets for molluscs, which make holes in leaves and leave tell-tale trails of slime. The good news is, you can control slugs organically. Make hunting for slugs and snails part of your evening routine and you’ll soon reduce their numbers. Choose slug resistant plants, and you could also make a homemade garlic spray to repel slugs.

How to get rid of vine weevil, leatherjackets and carrot fly

You may not see these pests until they have done their damage, as it's the larvae rather than the adults that cause the biggest problems. Adult vine weevils will chew the edges of leaves, but it’s their larvae, hiding in the soil and munching on the roots, that can kill a plant. Potted plants are most at risk, so if you see notches in the edges of your plant’s leaves, tip it out of the pot to inspect the roots for white grubs. Similarly, it’s the grubs of craneflies (known as leatherjackets) and carrot root fly that cause the damage. Use nematodes to kill vine weevils and leatherjackets organically. Two of the best ways to avoid carrot root fly are to grow resistant varieties of carrot and sow your seeds thinly to avoid the need to thin out seedlings, as this attracts the fly.

Aphids

Greenfly, blackfly and whitefly are abundant in spring and summer, breeding at a seemingly unstoppable rate. Drawn to tender new growth, they can be found on most plants. When aphids attack in large numbers, plant growth becomes distorted, the leaves curl up, the plant weakens and in severe cases the plant can die. Encouraging beneficial predators, such as ladybirds, lacewings and small birds into your garden, is one of the best ways to get rid of aphids. You can also try washing the aphids off or making a homemade soap spray.

How to get rid of ants

Ants are rarely a problem in gardens. However, sometimes they make a home inside garden pots – you’ll notice your plant isn’t thriving and there are ant tunnels in the compost. You can try to flush ants out of pots by repeatedly drenching the compost – although take care not to drown your plants.

Beetles and bugs

Beetles play an important role in the garden. Many species of ground beetle eat slugs, for example. However, some can cause problems. If you grow lilies or fritillaries, you’re likely to find small red beetles on your plants. These are lily beetles and they and their grubs eat lily foliage, often stripping the plants of all their leaves. Pick off the grubs and adults as soon as you see them, and crush them underfoot. Other beetles to keep an eye out for are the shiny, green rosemary beetle on rosemary, lavender and thyme, flea beetles on brassicas, wallflowers and other plants, and viburnum beetles, which can strip a viburnum of its foliage.

How to get rid of caterpillars

There are around 2500 species of moth in the British isles and over 50 species of butterfly. Most complete their lifecycles without us noticing. However the caterpillars of some, such as the large and small white (known as cabbage white caterpillars) can wreak havoc on cabbages and other brassicas.

There's a new caterpillar on the gardening scene and its target is box plants. The box tree caterpillar is fairly new to the UK, and can completely strip a plant of its leaves, killing it. The first thing you’re likely to notice is webbing across the leaves, and the box caterpillars feeding within. Try removing caterpillars by hand. Mixed nematodes sold to protect fruit and vegetables, and organic insecticides containing pyrethrins, may help to control infestations. If you are happy to use inorganic chemicals in your garden, a systemic neonicotinoid insecticide can be tried. However, the most effective solution is to grow alternatives to box, such as Ilex crenata and yew (Taxus baccata), and other evergreens, as only box plants are affected.

How to get rid of rats

Rats can make their homes under decking, in sheds or greenhouses, and even in compost heaps. The first step you can take to try to get rid of them is to block access to these places. Stop feeding birds and other wildlife, as this may be attracting rats. Keep your garden tidy, and move things around, placing obstacles in paths they regularly use, as rats don’t like change.

How to keep grey squirrels out

Squirrels are lovely to watch, but they can be a nuisance, digging up bulbs and raiding bird feeders. You can protect bulbs growing in pots by fixing chicken wire over the top. Use squirrel-proof bird feeders and position the feeders so it is difficult for squirrels to climb or jump onto them. And if you’re growing fruit, grow it inside a fruit cage.