Diagnose by symptom
Plants chewed at the base or roots
Seedlings cut off just above ground, chewed roots and tubers, sudden collapse of single plants — these are soil pests:
Pests
Cutworms
Thick, fat caterpillars of noctuid moths, grey-brown or earth-coloured, with smooth skin, feeding at night. During the d…
PestMole cricket
A large (3-5 cm) brown insect with massive, shovel-shaped front legs adapted for digging and resembling the paws of a mo…
PestWhite grubs (cockchafer larvae)
Large, fleshy larvae of cockchafers (common and forest cockchafer), growing to 4-6 cm, cream-white and C-shaped, with a …
PestWireworms (click beetle larvae)
Larvae of click beetles: narrow, hard and shiny, yellow-brown (hence the name 'wireworms'), up to 2-3 cm long, with thre…
PestVoles
Small rodents with a stocky body, short tail and blunt muzzle, about 9–13 cm long, active all year round. They dig shall…
PestVine weevils
Weevils 8-12 mm long, black or dark brown, with a short, broad snout, flightless and active at night. Their larvae are w…
Frequently asked questions
What is cutting my seedlings off at the base?
Seedlings cut off at the base are usually the work of cutworms – night-active moth caterpillars that feed just above the soil surface. Grubs (chafer larvae), wireworms and the mole cricket can also gnaw at the base, damaging roots and the root collar. Plants suddenly wilt and topple over, though they look untouched above ground.
How do I recognise cutworms in the soil?
Cutworms are grey-brown, plump caterpillars 2–4 cm long that curl into a characteristic C-shape by day and hide in the soil near the plant. You will find them by scraping back the top layer of soil around a severed seedling, especially in the evening. The damage shows as cleanly cut stems and plants lying on the ground.
How do I protect transplants from being cut at the base?
Place protective collars of cardboard or plastic around the root collar, pushed a few centimetres into the soil, so cutworms cannot reach the stem. Cultivate the soil regularly, collect caterpillars in the evening, and dig over beds in autumn to destroy overwintering stages. Controlling weeds and keeping the soil clean around young plants also helps.