Cutworms

The Problem

  • Cutworm larvae eat tender sprouts and plant shoots. They ruin a crop before it has a chance to get started.

Appearance:

  • The adult cutworm moth may look like just another innocent insect, flying around minding its own business. It’s actually hunting for a place to lay its eggs.
  • The larvae you may never see, but you’ll definitely see the damage they do.

Signs of damage

  • The telltale sign of a cutworm is a seedling stem that has been clipped off close to the soil surface. Usually the top part of the plant is left untouched, lying by the chewed-off stem.
  • Cutworms eat all garden vegetables and they like flowers, as well.
  • Cutworms especially like tender seedlings and young transplants. Spring plantings suffer the greatest damage.
  • Some cutworms climb up plants to feed on buds, shoots and foliage.
  • Leaf damage such as holes or ragged edges could be confused with slug damage, but if there is no slime trail, you may be dealing with cutworms.

Controls

  • Controlling weeds, grasses and plant debris both in and around the garden is an important preventive step because it reduces habitat and food favored by cutworms.
  • Tilling the garden in early spring and fall can help kill cutworms or pupae or expose them to the weather and to predators such as birds.
  • One way to keep cutworms from destroying your seedlings is to create a barrier to keep cutworms out. Use row covers over or cardboard collars (think toilet paper rolls) around transplants.
    • Be sure the barrier extends into the soil to keep burrowing worms out.
  • Another approach is the use of Bacillus thuringiensis (Bt), a naturally occurring bacterium that target many caterpillar-type pests. It can be an effective and environmentally friendly way to treat cutworms in the garden.
  • Parasitic nematodes are also effective against the larvae in their early stages below the soil line.
Scroll to Top