In Colorado and the high plains, pest specialists say it’s going to be a banner year for cutworms and their adult form, miller moths. Most nongardeners think miller moths are a nuisance because they fly in every open door and window on summer evenings, hovering around all your lights. Gardeners, however, know cutworms as the horrid creatures that spend their late Spring nights decapitating your young garden plants. They especially like broccolis and cauliflowers but are happy to eat through the stem of your young tomato plants and peas too.
The easiest way to control cutworms is to pick them up and throw them out to birds to eat or dispose of them in some way. These larvae are quite large and light colored so they are easy to see if you happen to be crawling through your garden. They are most fond of overwintering under broadleaf weeds in your garden….so weeding your garden thoroughly in Fall is a good deterrent.
If you’ve had problems with cutworms in the past, you may want to grow broccoli and cauliflowers indoors to transplant rather than direct seed in the garden. When it’s time to plant out into the garden, a small collar around the stem of the plant is all it takes. Saving all those empty toilet rolls is the most common collar, although plastic collars cut from water bottles or yogurt containers are also popular. Simple Dixie cups with the bottom cut out works well. Why do collars work? The cutworm doesn’t just start eating at one end of the stem and eat through…it wraps itself around the stem and then chews. All you have to do is keep it from wrapping around the stem and your plant is safe.
If, alas, you go out and find some plants decapitated, take a moment to look through the top inch or so of soil around the plant. You should find a nice fat cutworm resting from its big meal. Pick it out so that at least that cutworm won’t be a threat to the neighboring plants.
A video from Oklahoma on controlling cutworms: http://www.youtube.com/watch?v=v1T3wUp1AwE
Extension Slide Series http://tealeafgardens.wordpress.com/2013/04/03/a-toilet-roll-in-the-garden/