Cutworms: How to Identify and Stop Them

How to identify cutworm damage

The signature sign is seedlings or transplants cleanly cut off at the soil line and toppled, often overnight. Damage is worst early in the season when stems are small and tender.

• Smooth brown or gray caterpillars that curl into a C when touched
• Found on or just below the soil surface near damaged plants
• Active at night; plants look fine at dusk and are cut by morning

Least-toxic management, in order

1. 1Collars — Ring each transplant with a collar pushed 1-2 inches into the soil and standing at least 3 inches tall to physically block the caterpillars.
2. 2Gritty barriers — Surround stems with crushed oyster shell, sand, or diatomaceous earth.
3. 3Handpick at night — Search the soil surface after dark and drop cutworms into soapy water.
4. 4Cultivate soil — Till in spring or fall to expose overwintering larvae to freezing and predators.

When to escalate

If collars and barriers are in place but seedlings keep disappearing, confirm the culprit by scouting at night, since slugs and other pests cause similar damage. Contact your regional Extension office for identification help before applying any product.

✔ Set out transplants a little later, once soil warms, so plants grow past the most vulnerable seedling stage faster.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• University of Minnesota Extension — Cutworms — Cutworm appearance, C-shape behavior, night feeding, and cut-at-soil-line damage
• University of Massachusetts Extension — Insect Management in the Home Vegetable Garden — Collar dimensions and placement, gritty barriers, and tilling to disrupt overwintering

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