Wireworms
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Fix the cause, not the leaf
No spray will help here. The trigger is soil, water supply, nutrition or temperature, so change the growing condition and judge the result on new growth, not on damaged leaves.
Soil and crop debris
It waits in the ground or in last season's debris, so removing the plant does not clear the bed. Rotation and debris removal are the working controls.
It carries over to next season in soil, debris or seed — which is why rotation matters here, not just treatment.
Safe to compost
No pathogen carries over on this material, so it can go on an ordinary heap with the rest of the garden waste.
When and where to look
Scout the planting while temperatures hold between 8°C and 25°C.
Rule these out first
Same category, and at least one host crop in common — so they are genuinely confusable in the same part of the garden.
The signs that lead here
Full problem lists for these crops
About
Wireworms are the larvae of click beetles and spend three to five years in the soil before pupating. They are the classic problem of a bed made from old grassland — the population arrives with the turf and takes several years of cultivation to decline.
Symptoms
Narrow, clean holes bored straight into potato tubers, carrots and other roots, often with secondary rot following. Seedlings and young transplants wilt and die from stems chewed at soil level. The larvae are thin, tough, orange-brown and up to 25 mm long.
Organic Treatment
Trap them: bury pieces of potato or carrot on skewers 10 cm deep every metre, lift them twice a week, and destroy the wireworms clustered inside. Cultivate repeatedly in autumn and winter so birds can take them and frost reaches them.
Chemical Treatment
No soil insecticide is available for garden use. Time and cultivation are the only realistic controls.
Prevention
Do not plant potatoes and root crops in the first two years after breaking up grass — grow brassicas, beans or salads instead. Lift maincrop potatoes as early as possible, since damage accumulates the longer tubers stay in the ground.
Crops at risk
Related problems
Wireworms risk by location
Each location has a month-by-month profile computed from the weather archive: how many hours a year actually meet this disease’s thresholds.