PEST GUIDE
How to identify and manage cutworms
Young plants severed at soil level overnight. Identify the cause, protect the listed crops and use proportionate control.
13 sections
Identification
Cutworms are smooth grey-brown moth caterpillars that curl into a C shape when disturbed. They hide just below the soil by day and sever young stems near ground level, often beside a wilted or missing seedling.
Grey brown caterpillars hide in soil by day and curl when disturbed.
The relevant stage and feeding site are: Grey brown caterpillars hide in soil by day and curl when disturbed. Similar symptoms can come from weather, nutrient stress or another pest. Confirm fresh feeding or the relevant life stage before removing plants or taking control measures.
UK seasonality and monitoring
Cutworms are often noticed in spring and early summer when seedlings are small.
During this period inspect Seedlings and newly transplanted vegetables, concentrating on the crop stage and plant parts described above. Note when and where fresh injury appears; old feeding marks can remain after the pest has moved on.
Crops and plants affected
The recorded hosts are Seedlings and newly transplanted vegetables. This list identifies plants worth checking; it does not mean every crop is equally vulnerable. Start with the listed plants and inspect the tissue where this pest feeds.
Check affected crops for these signs: Young plants severed at soil level overnight. Match the symptom to a live pest, larva, egg or characteristic feeding sign before deciding that treatment is needed.
Damage and likely consequences
Young plants severed at soil level overnight. A small amount of old damage on a vigorous plant may be cosmetic. Continued feeding on roots, seedlings, growing points or edible parts can reduce establishment or yield.
On Seedlings and newly transplanted vegetables, judge severity by checking whether injury is fresh and spreading, whether the plant is still growing, and whether the edible part is affected. Avoid removing a crop based on one ambiguous mark.
Prevention
Clear weeds and plant debris before sowing vulnerable rows, then inspect seedlings as they establish.
Control and integrated management
Search the soil beside a freshly cut seedling and hand-pick any caterpillar found.
Natural predators and wildlife-conscious choices
Encourage ground beetles and avoid broad soil treatments.
For cutworms on Seedlings and newly transplanted vegetables, use a barrier or hand removal only where it fits the crop and life stage. Keep any cover taut, inspect it for trapped wildlife, and remove it when protection is no longer needed.
Long-term management
Check new rows at soil level after emergence and protect replacement plants until stems toughen.
For cutworms on Seedlings and newly transplanted vegetables, record the bed, crop stage and date when fresh damage first appears. Those notes help time protection and monitoring before the same crop stage is vulnerable next season.
Common mistakes
A symptom alone is not a diagnosis. Cutworms are smooth grey-brown moth caterpillars that curl into a C shape when disturbed. They hide just below the soil by day and sever young stems near ground level, often beside a wilted or missing seedling. Look for a matching live pest or fresh feeding sign before intervening.
A seedling cut at soil level may point to a cutworm; check around the stem before blaming birds.
If damage continues
Recheck Seedlings and newly transplanted vegetables where new injury is appearing, including the hidden feeding site: roots, folded leaves, leaf undersides, flowers or fruit as appropriate. If identification remains uncertain, photograph a live specimen alongside the damage and ask an allotment association or horticultural adviser.
If the recommended control (Hand search soil at dusk, remove larvae and replace damaged plants after checking the bed.) has not helped, confirm that it was fitted or applied at the right crop stage and that fresh damage is still occurring. Old marks do not heal when the pest has gone.
Frequently asked questions
Where should I look for a cutworm beside a missing seedling?
Cutworms are smooth grey-brown moth caterpillars that curl into a C shape when disturbed. They hide just below the soil by day and sever young stems near ground level, often beside a wilted or missing seedling. Check Seedlings and newly transplanted vegetables, especially at the feeding site described above. Hand search soil at dusk, remove larvae and replace damaged plants after checking the bed.
When should I start checking for cutworms?
Cutworms are often noticed in spring and early summer when seedlings are small.
How can I tell whether cutworms are still active?
Look for fresh damage and the relevant life stage. Young plants severed at soil level overnight. Old marks may remain after the pest has moved on.
What wildlife-conscious approach works for cutworms?
Encourage ground beetles and avoid broad soil treatments. Check covers and traps frequently, and remove them when the vulnerable crop stage has passed.