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Quick Answer
The most common UK garden pests are aphids, slugs and snails, vine weevils, lily beetle, box tree moth caterpillars, and winter moth caterpillars. For most of these, a combination of hand picking, encouraging predators, and physical barriers gives good control. Chemical controls are a last resort, used when the infestation is serious and other methods have failed. The single most effective thing you can do is encourage birds, frogs, hedgehogs and beneficial insects into your garden.
If you only do one thing, stop using broad spectrum insecticides. They kill the predators as well as the pests, and the pests bounce back faster.
An Integrated Approach to Pest Control
Pest control in a garden is not about eliminating pests. It is about keeping them below the level where they cause serious damage. A garden with no pests is a garden with no pest predators, and the first pest that arrives will run riot. The aim is a balance, where predators and pests keep each other in check.
The most effective pest control in any UK garden is a healthy population of birds, frogs, toads, hedgehogs, ground beetles, ladybirds, lacewings and hoverflies. These predators do most of the work for free, if you give them the habitat they need. A garden with a pond, a hedge, a wild corner, and a bird feeder will have far fewer pest problems than a sterile lawn and paving garden.
The 10 Percent Rule
If less than 10 percent of your plants are affected by a pest, do nothing. The predators will find the pest and deal with it. Hand pick if you must, but do not spray. Most pest outbreaks in a balanced garden never reach the level where they cause real damage.
Aphids
Aphids, also known as greenfly and blackfly, are small sap sucking insects that cluster on the soft growing tips of plants. They are the most common pest in UK gardens, affecting roses, broad beans, runner beans, dahlias, nasturtiums, fruit trees and many ornamental shrubs.
Identification
Aphids are 1 to 3mm long, soft bodied, and usually green or black but sometimes pink, brown or grey. They cluster on the undersides of leaves and on growing tips. The leaves may be curled, distorted, or sticky with honeydew, which is the sugary waste that aphids excrete. Black sooty mould often grows on the honeydew.
Damage
Aphids weaken the plant by sucking sap, distort new growth, and can transmit virus diseases between plants. On roses they cause curled leaves and poor flowering. On beans they can reduce the crop. On tomatoes and cucumbers in the greenhouse they can transmit viruses.
Control
- Hand pick or squash: for small infestations, simply rubbing the aphids off with your fingers or gloved hand is effective.
- Blast with water: a strong jet from the hose dislodges aphids and they rarely climb back up.
- Encourage ladybirds and hoverflies: both are voracious aphid predators. Plant marigolds, poached egg plant, and other flat flowered annuals to attract them.
- Soapy water spray: a teaspoon of washing up liquid in a litre of water, sprayed onto the aphids, kills them by suffocation.
- Biological control: in greenhouses, parasitic wasps such as Aphidius can be bought and released.
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Slugs and Snails
Slugs and snails are the number one pest in most UK gardens, particularly in wet years and on heavy soils. They eat the leaves and shoots of a wide range of plants, with hostas, dahlias, delphiniums, salad crops and seedlings being particular favourites.
Identification
Slugs and snails are easy to identify by the slimy trails they leave behind. The damage is irregular holes in leaves, often starting from the edge, and entire seedlings eaten off at the base. Check under pots, boards, and at the base of plants in the early morning.
Control
- Hand picking: go out at dusk or dawn with a torch and pick them off by hand. Drop them into soapy water. Repeat nightly for a week and you will dramatically reduce the population.
- Beer traps: sink a small container of beer into the soil. Slugs fall in and drown. Empty and refill every few days.
- Copper barriers: copper tape around pots gives slugs a mild electric shock and deters them.
- Encourage predators: frogs, toads, hedgehogs, and ground beetles all eat slugs. A pond is the best thing you can do for natural slug control.
- Nematodes: the biological control Nemaslug contains nematodes that parasitise slugs. Apply to moist soil in spring and autumn.
- Pellets: ferric phosphate pellets are the only slug pellets safe for wildlife and pets. Avoid metaldehyde pellets, which are now banned in the UK.
See our hosta profile for specific advice on protecting hostas from slug damage.
Vine Weevils
Vine weevils are among the most destructive pests in UK gardens, particularly in containers. The adult weevils eat notches out of the edges of leaves, but the real damage is done by the grubs, which eat the roots of plants and can kill a mature specimen in months.
Identification
Adult vine weevils are black, 8 to 10mm long, with a distinctive snout. They cannot fly but walk at night. The notches in leaves are a clear sign. The grubs are white, C shaped, with brown heads, found in the soil around the roots of affected plants.
Plants affected
Vine weevils particularly affect plants in containers: rhododendrons, azaleas, camellias, heucheras, primulas, fuchsias, and strawberries. They also attack plants in the open ground but are less obvious there.
Control
- Adult trapping: go out at night with a torch and pick adult weevils off the plants. Drop into soapy water.
- Nematodes: the biological control Nemasys contains nematodes that kill vine weevil grubs. Apply to moist soil in August and September when the grubs are small.
- Repotting: if a container plant is affected, knock it out of the pot, wash the roots, and repot in fresh compost. The grubs are in the old compost.
- Chemical control: provado vine weevil killer (acetamiprid) is the main chemical option for containers. Use sparingly as it affects bees.
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Lily Beetle
The lily beetle is a bright red beetle that attacks lilies and fritillaries. Both the adults and the larvae eat the leaves, and a serious infestation can defoliate a plant completely.
Identification
Adult lily beetles are 6 to 8mm long, bright red above and black below. They are slow moving and drop off the leaf when disturbed, often landing on their backs to expose the black underside. The larvae are orange, soft bodied, and cover themselves in their own excrement, which makes them look like small brown blobs.
Control
- Hand picking: the most effective control. Check lilies and fritillaries weekly from April. Hold a container of soapy water under the leaf before disturbing the beetle, so it drops in.
- Crushing larvae: the larvae are unpleasant to handle because of their excrement covering, but squashing them is effective. Use a stick or wear gloves.
- Chemical control: for serious infestations, a pyrethrum or neem oil spray is effective and less harmful to bees than synthetic insecticides.
Box Tree Moth
The box tree moth is a relatively new pest in the UK, first recorded in 2008 and now widespread across southern England. The caterpillars defoliate box plants and can kill a mature hedge in a single season. See the RHS guidance on box tree caterpillar for more detail.
Identification
The adult moth is white with a brown border, but you are more likely to see the caterpillars. These are green and yellow, up to 4cm long, with black stripes and black spots. They hide in webbing among the box leaves. The first sign is usually patches of pale leaves and webbing, then defoliation.
Control
- Pheromone traps: hang a pheromone trap in late April to catch male moths and reduce mating. This also tells you when to look for caterpillars.
- Hand picking: remove the caterpillars and webbing by hand. Best done in late afternoon when the caterpillars are active.
- Bacillus thuringiensis: a biological spray that kills caterpillars but is harmless to other wildlife. Available as a bacterial spray.
- Replacement: if your box is repeatedly devastated, consider replacing with alternative evergreens such as yew or Japanese holly.
Winter Moth Caterpillars
Winter moth caterpillars are the small green caterpillars that appear in spring on apple, pear, cherry and plum trees. They eat the leaves and the blossom, and can seriously reduce the fruit crop.
Identification
The caterpillars are pale green with yellow stripes, up to 2cm long. They hang from the tree on silk threads when disturbed. The damage is holes in the leaves and damaged blossom in April and May.
Control
- Grease bands: wrap a grease band around the trunk of the tree in October to catch the wingless female moths as they climb up to lay eggs. This is highly effective.
- Hand picking: for small trees, pick off the caterpillars by hand in April.
- Bacillus thuringiensis: a biological spray for serious infestations on larger trees.
Other Common Pests
Cabbage white butterfly caterpillars
The caterpillars of the large and small cabbage white butterflies eat the leaves of brassicas. Control by hand picking, by covering plants with fine netting to prevent egg laying, or by spraying with Bacillus thuringiensis.
Rose slug sawfly
The larvae of the rose slug sawfly eat the surface of rose leaves, leaving a skeletonised appearance. Control by hand picking or by spraying with soapy water.
Red spider mite
Tiny mites that suck sap from the underside of leaves, particularly in greenhouses. The leaves develop a mottled appearance and fine webbing. Increase humidity to discourage them, and use a biological control with the predatory mite Phytoseiulus in greenhouses.
Capsid bugs
Small green bugs that suck sap from the growing tips of many plants, leaving distorted leaves with small holes. Control by weeding around the plants to remove overwintering sites, and by tolerating the damage on established plants.
Ants
Ants do not directly damage plants but they farm aphids for their honeydew, protecting them from predators. Control ants by pouring boiling water on nests in paving, or by using ant bait stations. See our summer tidy checklist for general pest management.
Pest Control Calendar
| Month | Pest Active | Action |
|---|---|---|
| January | Winter moth | Apply grease bands to fruit trees |
| March | Aphids, slugs | Encourage predators, set beer traps |
| April | Vine weevil adults, lily beetle | Hand pick at night, check lilies weekly |
| May | Aphids, cabbage white, box moth | Hand pick, net brassicas, hang pheromone traps |
| June | Lily beetle, rose slug sawfly | Hand pick, spray with soapy water |
| July | Vine weevil grubs, red spider mite | Apply nematodes to containers |
| August | Vine weevil grubs, box moth second generation | Continue nematode treatment, hand pick |
| September | Slugs active again | Hand pick, set beer traps |
Encouraging Pest Predators
The single most effective pest control in any garden is a healthy population of predators. Here are the most useful and how to encourage them.
Birds
Blue tits and great tits are voracious caterpillar eaters, feeding their chicks on thousands of them through the spring. Put up nest boxes, provide food in winter, and provide water. Avoid using any insecticides during the breeding season.
Frogs and toads
Frogs and toads eat slugs, snails and other pests. A wildlife pond, even a small one, will attract them. Give them somewhere to hide during the day, such as a log pile or a stone pile in a shady corner.
Hedgehogs
Hedgehogs eat slugs, beetles and caterpillars. Provide access to your garden via a small gap in the fence, a hedgehog house, and avoid using slug pellets and insecticides. Hedgehog numbers have collapsed in the UK, so every garden that welcomes them helps.
Ground beetles
Ground beetles are nocturnal predators that eat slugs, vine weevil grubs, and other soil pests. Encourage them with a log pile, a wild corner with long grass, and minimal use of insecticides.
Hoverflies and lacewings
Both have aphid eating larvae. The adults feed on nectar from flat flowered plants such as marigolds, poached egg plant, fennel, dill, and yarrow. Plant a row of these among your vegetables.
The Predator Garden
A garden designed for predators has: a pond of any size, a hedge rather than a fence, a wild corner with long grass and nettles, a log pile, bird boxes and bird feeders, and a wide range of flowering plants including many native species. With these in place, most pest problems solve themselves.
When to Use Chemical Controls
Chemical controls are a last resort, used when the infestation is serious, other methods have failed, and the plant is at risk. When you do use chemicals, choose the most targeted option and apply it carefully.
Avoid broad spectrum insecticides such as those containing lambda cyhalothrin, which kill bees and other beneficial insects as well as the target pest. Choose targeted products and apply in the evening when bees are not flying. Never spray open flowers.
The range of chemicals available to home gardeners has shrunk dramatically in recent years, as the EU and UK regulators have withdrawn products that harm bees and other wildlife. This is a good thing. The remaining products are largely biological or botanical, and they work well when used correctly.
Frequently Asked Questions
Are slug pellets safe for wildlife?
Ferric phosphate pellets are safe for wildlife and pets when used as directed. Metaldehyde pellets, the older type, are now banned in the UK because they poisoned wildlife and pets. If you use slug pellets, choose ferric phosphate and use them sparingly.
How do I get rid of aphids on my roses?
Start by squashing them by hand or blasting them off with the hose. Encourage ladybirds and hoverflies by planting flat flowered annuals nearby. If the infestation is serious, spray with soapy water or a pyrethrum based spray in the evening.
What is eating my hostas?
Almost certainly slugs or snails. Check the underside of the leaves and the soil around the plant at dusk. Hand pick, set beer traps, and apply nematodes in spring. See our hosta profile for full details.
Why are there so many caterpillars on my box hedge?
This is box tree moth caterpillar, a serious pest of box. Pick them off by hand, remove the webbing, and spray with Bacillus thuringiensis. Hang a pheromone trap in spring to monitor for the moth. If the box is repeatedly defoliated, consider replacing with yew or Japanese holly.
Should I use biological controls?
For specific pests in specific situations, biological controls are very effective. Nematodes for slugs and vine weevils, parasitic wasps for greenhouse aphids, and Bacillus thuringiensis for caterpillars are all worth trying. They are more expensive than chemicals but are targeted and wildlife friendly.
Final Thoughts
Pest control in a garden is about balance, not elimination. A garden with no pests is a garden with no predators, and the first pest to arrive will run riot. The aim is to build a garden where predators do most of the work, where pests are kept at a manageable level, and where chemicals are a rare last resort.
It takes a few years to build this balance. Start with a pond, a wild corner, and a ban on broad spectrum insecticides. Add bird boxes, a log pile, and a wide range of flowers. Within three or four years you will find that pest problems have become far less frequent and far less serious.
Further Reading
In mature and established gardens, always assess the existing ecosystem before making changes. Small adjustments to timing and technique can preserve decades of growth and wildlife value.
Put this advice into practice
Use the relevant CGM tool or follow a related guide, then send us a few photos if you would like a tailored plan.
Sources and citations
This article draws on the following sources. Specific claims are cited inline where relevant.
- CGM field records (2025-07. Site observations from gardens across Oxfordshire, Buckinghamshire, Berkshire and Bedfordshire.
- Royal Horticultural Society (2024). RHS Gardening Advice and Plant Finder. Available at rhs.org.uk.
- Met Office (2024). Regional climate averages, South East England. Available at metoffice.gov.uk.
- British Geological Survey (2024). Soil parent material data for the Chilterns and Thames Valley. Available at bgs.ac.uk.