Before planting a new garden remove weeds and plant debris that might feed and shelter developing larvae.
Turn the soil during preparation then give birds and other predators a chance to pick off the expose larvae and pupae.
Mow as closely as possible to the edge of your garden to give cutworms less to feed on and less shelter near your plants.
A three-foot wide (or more) bare-soil strip between your lawn and your garden plants makes it harder for larvae to reach your plants. It also gives you more of a chance to spot them.
Wait as late as possible before setting out starts. Cutworms go on the move early in the growing season. Give them a chance to starve before you put out dinner.
Place cardboard collars (or milk containers with the bottom cut out) around transplant stems at planting time. Be sure to work the collar into the soil at least an inch or two.
Plant sunflowers along the edge of your garden. Sunflowers are a favorite target of cutworms. The plants will attract the larvae giving you a chance to pick them from the ground before they head to your corn.
Dealing with Infestations
The presence of many birds feeding in the yard may indicate cutworms in your turf.
Handpick caterpillars after dark. This is often most productive following a rain or thorough watering.
Slow the progress of worms, who don’t like navigating dry soil, by watering in the morning then cultivating your garden’s walkways lightly to a depth of an inch or so. This cultivated soil will dry quickly while trapping moisture beneath it. Do not use mulch which gives the worms shelter.
Beneficial nematodes released in moist, spring soil will attack and destroy cutworms living underground. They’re especially beneficial to apply the season after cutworms have been a problem.
At the first sign of moths, release trichogramma wasps weekly for three consecutive weeks to parasitize cutworm eggs.
Spreading a line of diatomaceous earth around the base of plants sets up a barrier to larvae. Diatomaceous earth, the fossilized, abrasive remains of prehistoric sea life, literally lets you draw a line in the dirt that’s deadly to any larvae that pass over.
Scatter bran or corn meal mixed with Monterey Bt (Bt-kurstaki) and molasses on the soil surface to attract and kill caterpillars. Eco-Bran will also kill caterpillars that feed on it.