Cutworm Infestation in a Garden

Euxoa messoria cutworm (via Wikimedia Commons, CC BY 3.0 US)

Cutworm infestations in a garden can be a serious problem for gardeners, as these pests can cause significant damage to young plants. Cutworms are the larvae of certain species of moths, and they feed on the stems and leaves of a wide variety of plants.


  • Wilted or broken seedlings or young plants, which may be cut off at soil level or have damage near the base of the stem.
  • Damage to the stem near the soil line, which may appear as a ragged or chewed area. This can cause the plant to weaken and become more susceptible to disease.
  • Chewed or ragged leaves, which may have holes or missing sections. This can make the plant less able to photosynthesize and grow properly.
  • Presence of cutworm larvae or adult moths, which may be visible on the plants or in the surrounding soil. The larvae are typically 1-2 inches in length and have a dark or mottled colored body. They may be curled up when disturbed and have a smooth, plump, and soft-bodied appearance. Adult moths are typically brown or gray in color and have a wingspan of 1-1.5 inches.

It is important to note that not all the symptom may be present in every infestation and other pests or disease may have similar symptoms. Gardeners should consult with their local extension office or a plant specialist to correctly identify the infestation.

What is a Cutworm

  • Typically 1-2 inches in length, but can vary depending on the species and stage of development
  • Dark or mottled colored body, with shades of gray, brown, black, or green
  • Often curled up when disturbed, but may also be found lying on the surface of the soil or hiding in the base of plants
  • Smooth, plump and soft-bodied, with a slightly curved shape
  • Can have small hairs on the body, which may be used to sense its environment
  • Has a segmented body with three pairs of true legs near the head and five or six pairs of prolegs on the abdomen
  • May have a distinct head, thorax and abdomen
  • May have a shiny or glossy appearance
  • Some species have a distinct pattern on their body
  • Some species can have a yellow or orange band on the body

It is important to note that the appearance of cutworm larvae can vary depending on the species and stage of development. Gardeners should consult with their local extension office or a plant specialist to correctly identify the infestation.

Treating a Cutworm Infestation


  • The most simple and straightforward method, this involves physically removing the cutworm larvae from the garden.
  • Gardeners can check plants for signs of damage and look for the larvae during the day or at night with a flashlight.
  • The larvae can then be disposed of by dropping them in soapy water or squishing them.
  • This method can be effective, but it can also be time-consuming and may not be feasible for larger infestations.
  • Handpicking can be especially effective when used in combination with other methods like using barriers, as it can help to keep the population under control while other methods take effect.

Using Biological Control

  • This method involves using other organisms to control the cutworm population.
  • Examples of biological control include using parasitic wasps, nematodes, or birds to target the cutworm larvae.
  • Some parasitic wasps are effective against cutworm, these wasps will lay their eggs on the cutworm, the eggs will hatch and the wasp larvae will feed on the cutworm.
  • Nematodes are tiny worms that can be applied to the soil, they will seek out and kill cutworm larvae.
  • Birds like robins, thrushes and blackbirds feed on cutworm larvae, making them a good biological control, however, it may not be feasible to attract birds in every garden.
  • This method can be effective, but it can take some time for the biological control organisms to establish and control the cutworm population.

Using Chemical Pesticides

  • This method involves using chemical pesticides to kill the cutworm larvae.
  • Gardeners should choose a pesticide that is specifically labeled for cutworm control and follow the instructions on the label.
  • Chemical pesticides can be effective, but they can also harm beneficial insects and other organisms in the garden.
  • When using pesticides, it is important to follow the label instructions and use the appropriate amount. Overuse of pesticides can not only damage the environment but also make the pests more resistant to the chemicals.
  • Some common chemical pesticides labeled for cutworm control include Bacillus thuringiensis, carbaryl, and pyrethrin.

Using barriers

  • This method involves using physical barriers to prevent the cutworms from reaching the plants.
  • Examples of barriers include using diatomaceous earth, a fine powder made from fossilized diatoms, or a collar made from cardboard or aluminum foil around the base of the plant.
  • Diatomaceous earth is a dust made from the fossilized remains of tiny aquatic organisms called diatoms. The dust will dry out the cutworm and cause them to die.
  • Collars made from cardboard or aluminum foil can be placed around the stem of the plant and buried a few inches into the soil, this will prevent the cutworm from reaching the stem and feeding on the plant.
  • This method can be effective, but it can be labor-intensive and may not completely control the cutworm population.