Cutworms and Armyworms

Cutworms and armyworms feed at night, severing young stems at the soil line or consuming foliage in large swaths. You will find wilted or toppled seedlings in the morning with no visible pest present. Dig gently around damaged plants to find the curled, gray-brown larvae just below the soil surface. Both pests are active from early spring through fall in Western Washington gardens and landscapes.

Cardboard or plastic collars around transplant stems block cutworm access at the soil line. Hand-pick larvae at dusk when they emerge to feed. Bt (Bacillus thuringiensis var. kurstaki) applied to foliage controls feeding caterpillars without harming beneficial insects. Encourage ground beetles and birds that feed on larvae. Tilling soil in early spring exposes overwintering pupae to predators.