✂️ Cutworm
Various species (Noctuidae)
The tiny lumberjack that fells your seedlings at midnight.
How to identify
Fat, smooth, dull-colored caterpillars (gray, brown, or black) up to 2 inches long that curl into a tight 'C' when disturbed — the classic cutworm pose. They're nocturnal, hiding in soil or debris by day, which is why the damage seems to appear by magic.
Damage signs
Chews through seedling stems at or just below the soil line, toppling healthy transplants overnight like tiny felled trees. Also climbs to feed on leaves and fruit of older plants.
Non-chemical controls
- Wrap cardboard, foil, or toilet-paper-roll collars around transplant stems, sunk an inch into the soil — the physical barrier stops them cold.
- Go out at night with a flashlight and handpick the culprits from the soil surface.
- Sprinkle diatomaceous earth in a ring around each seedling to shred soft cutworm bodies.
- Till the garden 2–3 weeks before planting to expose overwintering larvae and pupae to birds.
- Remove weeds and debris where cutworm moths lay eggs, and delay planting slightly if cutworms are active — starve them out before your seedlings arrive.
- Encourage ground beetles and birds, both enthusiastic cutworm predators.
Nerdy fact: Cutworms are the larval stage of miller moths — those dusty brown moths bouncing around your porch light. One female moth can lay hundreds of eggs, which is why a single porch light near the garden can seed next spring's seedling massacre.