Pests & diseases › Wireworm

Wireworm

Thin yellow-orange shiny grubs (larvae of click beetles). Tunnel through potatoes, root crops and onions.

Symptoms

  • Narrow tunnels straight through potato tubers
  • Holes through carrots, onions, beetroot
  • Stunted seedlings with roots eaten away
  • Worst on newly-cultivated grassland

Lifecycle

Larvae live in soil 4–5 years before pupating. Worst on land recently dug from grass.

What to do

  • Lift potatoes early — the longer they sit, the more damage
  • Trap with halved potato or carrot buried just below soil — lift every 2 days and destroy
  • Encourage robins, blackbirds, hedgehogs

If it's bad

  • No effective home-garden control

Stop it coming back

  • Cultivate often in the first 2–3 years after breaking ground
  • First and second early potatoes escape worst damage
  • Wireworm numbers drop sharply after 3 years of continuous cultivation

Crops it goes for

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.