13 common garden pests and how to treat them
Protect your patch from troublesome critters

Our gardens are living, breathing ecosystems: we share our lawns and flowerbeds with a myriad of creatures, from animals and insects to molluscs, invertebrates and more. While some are plain to see, others are invisible to the naked eye. For the most part, this rich abundance of wildlife is good news for our gardens and it's only when certain species cause significant damage that they're deemed pests and action needs to be taken. Here's how you can protect your plants and tackle some of the most troublesome critters.
Garden pest: alder leaf beetle

This metallic navy beetle loves nothing more than feeding on deciduous garden trees like beech, hazel, hornbeam and of course its namesake, alder. Emerging in the spring, its calling card is defoliated or bitten leaves, though it’s worth saying that alder leaf beetles are unlikely to affect the long-term health of the trees they feed on.
Alder leaf beetle: treatment

Garden pest: southern green shield bug

A small but deadly European critter, the southern green shield bug, also known as the southern green stink bug, can devastate fruit and vegetable plants including tomatoes, runner beans and raspberries. Feeding on the sap of these kitchen garden favourites, they cause odd, misshapen produce to grow, creating a similar effect to some garden diseases and disorders. These vibrant green insects are found across Europe, Asia and Africa, as well as in the south and east of the United States.
Southern green shield bug: treatment

Garden pest: moles

Moles: treatment

Garden pest: aphids

Aphids: treatment

You can squash them, dislodge them with a hose, shake them off onto a sheet or spray with a washing-up liquid solution. You can also encourage the aphid’s natural predators such as ladybirds and lacewings with nectar-rich flowers or herbs – pollinators like bees will thank you too – or purchase their larvae and introduce them as a biological control. There are also many different insecticides available, but read the instructions carefully and take precautions if you have pets or small children.
Garden pest: fuchsia gall mite

As any gardener knows, flowerbeds are the perfect way to add a splash of colour, especially if you're starting a new garden from scratch. However, this microscopic mite infests the young shoots at the top of the fuchsia, sucking its sap and distorting the foliage as well as causing abnormal growths from the chemicals it injects.
Fuchsia gall mite: treatment

Gall mites are resistant to pesticides so in an attempt to reduce the problem, remove any infected areas and either burn them or put them in the household waste. Choose species that are more resistant to infection from these little devils, such as 'Baby Chang', 'Cinnabarina', 'Miniature Jewels' and 'Space Shuttle'.
Garden pest: vine weevils

Vine weevils: treatment

Don your head torch and find the beetles at night; they tend to favour plants in containers. Pick them off or shake the plant into an umbrella. You can also check in the soil for larvae should you feel brave. A better option would be to use nematodes; an increasingly popular and safe method. These microscopic worms are watered into your soil to kill the beasties from the inside. Nice. Failing this, insecticides are available for use on ornamental plants in containers only.
Garden pest: cabbage white caterpillar

You may have spent all summer growing your own vegetable garden, but this very hungry caterpillar enjoys nothing more than munching the leaves of cabbages and other brassica plants, including cauliflower, kale and broccoli. Active around June to September, they can have a devastating impact on your patch.
Cabbage white caterpillar: treatment

Net your brassicas to stop cabbage white butterflies from laying eggs on them in the first place. When you spot the caterpillars, pick them off and leave them somewhere for the birds to feast on. Chemical treatments are available but these are then passed on into the food chain. It's better to use a nematode spray on the leaves in the evening, which infects the caterpillars with a bacterial disease. Who said gardening was a gentle past time?
Garden pest: lily beetle

A pretty bright red beetle that loves to take up residence on lilies, these colourful critters are not hard to find, but they're pretty hard to catch. Known for devouring leaves if not entire plants, these little Houdinis jump and disappear when they sense danger, leaving a trail of destruction in their wake.
Lily beetle: treatment

Take them by surprise and squash them. Brutal, I know, but the larvae they produce are coated in black excrement and also feed on the leaves, causing serious damage. Less time-consuming treatments include spraying neem oil, a natural insecticide, onto the leaves to kill larvae and repel adult bugs. Imidacloprid, a synthetic insecticide, can also help prevent infestations when applied to the surrounding soil in early spring.
Garden pest: pigeons

Growing your own food is one of life's simple pleasures but many a plot has been decimated by hungry pigeons. In particular, they enjoy eating the leaves of cabbages and making their way through everything from cauliflower, Brussels sprouts and broccoli to peas and cherries.
Pigeons: treatment

Garden pest: rabbits

Cute, yes, but rabbits can cause extensive damage by nibbling away at a huge range of plants and crops, digging holes and scraping up the lawn. They favour new young growth and gnawing at bark, which can ultimately kill the shrub or tree.
Rabbits: treatment

Garden pest: glasshouse red spider mite

A red sap-feeding mite that exists in colonies, these tiny bugs strike primarily across greenhouses and house plants. They cause a mottled appearance on the leaves, leading to eventual leaf loss, and, in the case of heavy infestations, the plant may even die.
Glasshouse red spider mite: treatment

Good hygiene in your greenhouse will help fend off this blight; thorough annual cleaning with a disinfectant, removing debris, weeding around the structure and avoiding overcrowding plants may minimise the chances of an infestation. This won’t totally prevent these pests but it will help. An easy gardening hack is to introduce predatory mites or midges, which are available by mail order, as well as other natural predators like lacewings and ladybirds.
Garden pest: greenhouse whitefly

Another houseplant and greenhouse inhabitant, this sap-sucking insect leaves a honeydew residue on its victims, which turns into a black sooty mould. Active all year round, it feeds on edible and ornamental plants, reducing their vigour.
Greenhouse whitefly: treatment

Make sure you have a clean greenhouse or cold frame and quarantine new plants before introducing them. Hang sticky tape to catch these flying pests and consider a biological control in the form of tiny parasitic wasps that can help to tackle the infestation. Many chemical options are available but do check the instructions for correct use.
Garden pest: slugs and snails

Slugs and snails: treatment

Whether its potted plants or flowerbeds, create barriers around your plants with garden repellants our grandparents used to use, from coffee grounds and crushed eggshells to wool pellets or copper tape – you could even set beer traps. Slug pellets offer a chemical option but be aware of the risks to wildlife, children and the environment. Instead, look into using nematodes or roundworms to destroy the larvae and encourage predators into your garden such as frogs, birds and hedgehogs.
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