Pests and diseases in the UK
What's eating it, what's wrong with it, and what to do. The app identifies these from a photo. Here's the list.
AphidsTiny sap-sucking insects, green, black or grey. Cluster on shoot tips, undersides of leaves and flower buds. Sticky honeydew below.BlackflyBlack aphids that swarm growing tips of broad beans, nasturtiums and beetroot.Slugs & SnailsSoft-bodied molluscs that leave silvery slime trails and chew ragged holes in leaves overnight.Late BlightDevastating fungal-like disease (Phytophthora infestans) of tomatoes and potatoes. Brown-black blotches on leaves, white fluffy mould below in damp weather.Potato BlightSame pathogen as tomato blight (Phytophthora infestans). Wrecks the foliage, then rots the tubers.Halo BlightBacterial disease of French and runner beans. Small angular brown spots ringed by a pale yellow halo.Chocolate SpotFungal disease of broad beans. Chocolate-brown spots and streaks on leaves, stems and pods.Carrot FlyTiny black fly whose larvae tunnel into carrot, parsnip, celery and parsley roots. Triggered by the smell of crushed foliage.Cabbage Root FlySmall white maggots eat the roots of all brassicas. Plants wilt and collapse for no obvious reason.Cabbage White ButterflyLarge and small white butterflies whose green and yellow caterpillars strip brassica leaves to ribbons.Club RootSoil-borne disease of all brassicas. Roots swell into grotesque clubs, plants struggle and fail.Powdery MildewWhite dusty fungal coating on leaves and stems. Worst on courgettes, squash, cucumbers and peas in dry summers.RustOrange-brown fungal pustules on leaves. Affects leeks, garlic, onions, mint, raspberries and beans.WhiteflyTiny white moth-like insects on leaf undersides. Plume up when disturbed. Suck sap, excrete honeydew.Flea BeetleTiny black beetles that ping into the air when disturbed. Pepper leaves of rocket, radish, mustard and brassica seedlings with shotgun-style holes.Leaf MinerTiny fly larvae tunnel between leaf surfaces leaving winding pale trails. Affects beetroot, chard, spinach and celery.Celery Leaf MinerSpecific leaf miner attacking celery, celeriac and parsnip foliage.WirewormThin yellow-orange shiny grubs (larvae of click beetles). Tunnel through potatoes, root crops and onions.Red Spider MiteMicroscopic mites on undersides of greenhouse crop leaves. Fine webbing in bad attacks. Worst in hot dry conditions.Cucumber Mosaic VirusViral disease spread by aphids. Hits cucumbers, courgettes, squash. Yellow mottling on leaves, distorted fruit.Asparagus BeetleDistinctive black-and-red beetle. Adults and grey-black larvae strip asparagus foliage in summer.CankerSunken cracked patches on parsnip shoulders, apple and pear branches. Allows rot to set in.Leek MothSmall moth whose caterpillars tunnel into leek, onion and garlic leaves and bulbs.Onion FlyMaggots tunnel into onion and shallot bulbs. Plants wilt and yellow.Onion White RotDevastating soil-borne fungal disease of onions, garlic and leeks. White fluffy growth on bulb base.White RotCatch-all name often used for onion white rot — fluffy white fungal growth on base of allium bulbs.Violet Root RotSoil-borne fungus covering asparagus, beetroot, carrot and parsnip roots with a purple web of mycelium.Crown RotSoft brown rot at the base of rhubarb, asparagus and strawberry crowns. Usually kills the plant.Lettuce Root AphidPale yellow aphids that colonise lettuce roots. Plants wilt and collapse in hot weather.Pea MothSmall moth whose caterpillars feed inside pea pods — the maggoty peas you find when shelling.Rhubarb Gall MidgeSmall midge whose larvae cause raised reddish blisters on rhubarb leaves. Mainly cosmetic damage.Colorado BeetleNOTIFIABLE pest in the UK. Yellow beetle with black stripes, devastating to potatoes. Report any sighting to APHA.BadgersProtected species. Will dig up beds for worms, raid sweetcorn, strawberries and root crops.MiceTake pea and bean seeds straight out of the soil, gnaw stored crops, raid sweetcorn.PigeonsWood pigeons strip brassica leaves to ribbons in winter and peck at seedlings year-round.BirdsBlackbirds, thrushes and starlings raid soft fruit. Sparrows tear pea seedlings.WaspsCommon wasps eat ripe and damaged fruit, especially plums, pears, apples and grapes.Pear PsyllaTiny sap-sucking insects on pear shoot tips. Honeydew leads to sooty mould.Raspberry BeetleSmall brown beetle whose grubs are the maggots you find inside raspberries and blackberries.Spotted Wing DrosophilaInvasive fruit fly (SWD). Females lay eggs in ripening berries — soft fruit collapses within days.
Plan the plot, track every sowing, cook the harvest
Sowing reminders and harvest forecasts for your own frost dates, the Seed Tin, Scan Centre for any label or packet, and the Potty Mouth Garden Club. Free to start.