What Is Eating My Lettuce Seedlings?

Lettuce seedlings are tender, low and irresistible, and finding them grazed to nubs, cut off at the base, or simply gone overnight is a common heartbreak. Several pests target young lettuce, and identifying yours quickly lets you protect the survivors and any reseeding. The pattern of damage and the time it appears point to the culprit. Let me walk you through the suspects.

Slugs and snails

The most common seedling-killers by far are slugs and snails — lettuce is among their favourite foods. If your seedlings are reduced to ragged stubs or have vanished entirely, and you see silvery slime trails on the soil in the morning, these are your culprits. They feed at night and in damp weather and can clear a row of lettuce seedlings in a single night. Hunt them after dark with a torch and hand-pick, set beer traps, clear damp hiding places, and ring the seedlings with a gritty barrier they dislike crossing. Slug control is the single most important thing for protecting lettuce seedlings.

Cutworms

If seedlings are found cut off cleanly at or just above the soil line, toppled as if snipped, the culprit is the cutworm — a soil-dwelling caterpillar that hides by day and chews through tender stems at ground level at night. They are devastating to young transplants. Protect each seedling with a collar — a cardboard tube or cut plastic cup pushed an inch into the soil — which physically blocks them. Clearing weeds and disturbing the soil before planting reduces their numbers.

Birds and other grazers

Birds can pull up or peck at lettuce seedlings, especially in spring, leaving them uprooted or shredded without slime trails. Netting or row cover over the seedbed keeps birds off. In some gardens, rabbits and other animals graze young lettuce to the ground — fencing or covers are the answer there. If seedlings are damaged in daylight with no slime and no clean-cut stems, birds or animals are the likely cause rather than slugs or cutworms.

Protect young lettuce

The best all-round protection is a physical barrier. Floating row cover laid over the seedbed excludes slugs to a degree, birds, and many insects, while letting in light and water — an excellent option for vulnerable lettuce seedlings. Cloches protect individual plants. Starting lettuce in modules or pots and transplanting sturdier young plants, rather than direct-sowing into a pest-prone bed, also helps them survive. Match the damage to the pest — ragged stubs and slime equals slugs; clean-cut toppled stems equals cutworms; daytime uprooting with no slime equals birds — then protect the rest, and shepherd your lettuce safely past the seedling stage, after which it grows quickly to a more resilient size.