Potatoes: Pests & Diseases
Potatoes are dependable crops for beds, bags and allotments, but they need a clear rotation and close attention in damp weather. Healthy seed potatoes, generous spacing and regular earthing up help produce cleaner tubers and reduce the impact of several common soil-borne problems.
Common pests
Potato cyst eelworm damages roots, leaving plants stunted, pale and disappointing. Slugs can tunnel into tubers, particularly in weedy or damp ground. Wireworm creates neat holes in tubers and is more likely after grass. Aphids feed on foliage and can spread viruses. Colorado beetle is not established widely in the UK, but any unfamiliar striped beetles or larvae should be reported through appropriate official channels.
Common diseases
Potato blight is the principal disease, with dark patches on leaves and stems followed by brown rot in tubers. Potato scab causes rough corky patches but rarely affects eating quality. Blackleg leads to blackened stem bases, wilting and rotting seed tubers. Viral diseases can produce mottling and poor growth. Tubers may also rot in storage if lifted wet or damaged.
Prevention
Use certified, healthy seed potatoes and grow resistant varieties where blight or eelworm has been troublesome. Rotate potatoes away from the same ground for at least four years, avoiding recently cleared grass if wireworm is likely. Earth up plants to cover developing tubers and prevent greening. Keep rows weed-free, remove volunteer potatoes, and avoid handling or harvesting plants when foliage and soil are wet.
Non-chemical control
Hand-pick slugs from traps and shelters, and reduce their cover by clearing weeds and debris around rows. Encourage ground beetles, frogs and birds by maintaining varied garden habitat. Lift early potatoes promptly once ready so slugs have less opportunity to feed. Remove blacklegged plants with their seed tuber. Cut down blighted foliage and dispose of it away from compost before lifting tubers.
What to look for
Check emerging plants for uneven, weak growth that could indicate eelworm, and examine leaves weekly for aphids or blight. After prolonged wet, warm weather, inspect plants every few days for dark blight lesions. At harvest, assess tubers for slug holes, wireworm damage, scab and rot before storage.
Tips
Earth up twice during growth, keeping all tubers covered. Harvest only when soil is reasonably dry and cure sound tubers briefly in a dark, airy place. Store in cool darkness, checking regularly and removing any tubers that soften or rot.
Potatoes pests & diseases: frequently asked questions
What are the common pests of potatoes?
Potato cyst eelworm damages roots, leaving plants stunted, pale and disappointing.
What diseases affect potatoes?
Potato blight is the principal disease, with dark patches on leaves and stems followed by brown rot in tubers.
How do I prevent pests and diseases on potatoes?
Use certified, healthy seed potatoes and grow resistant varieties where blight or eelworm has been troublesome.
General guidance for UK home gardens, focused on prevention and non-chemical control. The RHS or a local garden centre can help with tricky cases. Page updated 18 Sep 2026.