Extension Column - Cutworms are a real problemFew things are more frustrating than walking out to do some gardening, and finding all of your crops half eaten or destroyed. This summer, plant disease and insects have been a real problem.
By: Janelle Lanoue, U of M Extension intern, Alexandria Echo Press
Few things are more frustrating than walking out to do some gardening, and finding all of your crops half eaten or destroyed. This summer, plant disease and insects have been a real problem. We could place the blame on the unusual weather patterns, or even the unseasonably warm winter; either way, it’s that time of year again when more of us will be seeing intruders in our gardens. The past few weeks, the most common unwanted invader for gardeners around the community has been the cutworm.
Cutworms are the larvae of several species of night-flying moths. The larvae are called cutworms because they cut down young plants as they feed on stems at or below the soil surface. There are also species of climbing cutworms that move up plants and feed on foliage, buds and shoots. Most cutworms attack a wide range of plants including asparagus, bean, cabbage, carrot, celery, corn, lettuce, pea, pepper, potato and tomato.
Though there are many different variations of cutworm, most can be quite distinct from one another. Their coloring can vary from brown or tan to pink, green or gray and black. Some cutworms are uniform in color, while others are spotted or striped. The most distinctive characteristic is their ability to curl up into a tight “C” shape.
In most cases, it’s more likely that you’ll see the damage caused by cutworms before you see the cutworms themselves. It is very important to regularly check your garden, especially during late afternoon and evening hours when cutworms are more active. Watch for plants cut off near the ground, holes in the leaves, or plants that are noticeably wilting. You may also detect droppings on the ground, which can indicate cutworm feeding.
Catching cutworm activity when it first begins will make controlling and eliminating them much easier. Management steps are much more effective when the larvae are small. Here are some suggestions:
• Surround transplant stems with collars of folded newspaper, cardboard strips or aluminum foil. The collars should be 2 to 3 inches tall and pushed firmly into the soil so the cutworm can’t go over or under.
• Remove weeds and plant residue to help reduce egg-laying sites and seedling weeds that nourish small cutworms.
• Till your garden before planting as this helps expose and kill overwintering larvae.
• Water early in the day and loosen soil so the surface is dry by evening, or cutworm dinnertime.
• The use of insecticides can be used to protect plants if you are experiencing a severe problem. Treat the stems or the foliage. For the best results, apply insecticides in the evening.
Cutworms can have destructive and devastating effects on our gardens. If you are careful to take preventive measures, and keep a lookout to catch them early, cutworms will be much easier to cut out of your garden!
For more information on cutworms, please visit www.extension.umn.edu/distribution/horticulture/m1225.html