The Oklahoma gardener puts on a brave face when it comes to the heat and drought, poor soils and general unpredictability of gardening. However, there is something that strikes fear in the heart of every gardener – cutworms.

 

Cutworms aptly get their name because they cut down young plants while feeding on the stems. Often confused for grubs, they’re technically a type of caterpillar that turns into nocturnal moths once they mature.

 

Cutworms stay buried below the soil surface near food plants during the day before emerging at night to feed. During their feeding frenzy, they often chew through the seedlings or small stems, causing the plant to fall over and die. They curl around the stem to feed on it. They also feast on roots and foliage of young, vulnerable plants, often destroying the entire plant.

 

These garden pests are partial to grass and many weeds, so it’s important to remove grass and weeds in the garden. The larvae live under the soil, along with weeds and grass. Plow or till the garden plot well in advance of planting new plants.
In some cases, gardeners may not even realize they have a cutworm problem. This happens when the cutworms do all of their destruction from underground. It’s not until the plant shrivels and dies that the issue becomes apparent.

 

Gardeners should check their plants early in the morning when damage is fresh and easier to see, as well as in the late afternoon or evening when cutworms are more active. Should evidence of cutworms be found, there are several options for control.

• Maintain a 3-foot to 4-foot buffer of dry soil along the edges of the garden to make the space unattractive for cutworms.
• Physically remove and crush cutworms or drop them in a bucket of soapy water.
• Remove plant residue to reduce egg-laying sites
• Use compost instead of manure.
• Place sleeves around newly set transplants or newly emerged seedlings. The sleeve should be 1 inch below ground and 3 inches above. Small paper cups with the bottoms removed or a 4-inch-high section of a paper milk carton work well. A twig, straw, or popsicle stick placed next to the stem of young plants also inhibits the caterpillar from wrapping around the stem and cutting through it.
• Foil wrapped around the base of the plant is another option.

 

Control of cutworms is most effective when the larvae are small. Crops such as tomatoes, peppers and celery may need monitoring through harvest.

 

Pesticides typically aren’t necessary in the home garden, but if experiencing severe problem, these products can be applied to the stems or leaves. Apply the pesticide in the evening right before cutworms come out to feed. Be sure to read all label directions on the container. The earlier gardeners detect cutworms, the easier they are to control.

Oklahoma State University Extension offers additional gardening information online.