A few decades ago when I first started vegetable gardening at my home in Chisago County, I’d see some of my tomato plants cut right off at the soil level leaving the entire top totally cut off from the base of the plant and the roots. I had no idea what was going on. After a couple of years of this I finally found out that the problem was cutworms.
Now I knew from watching my grandpa garden, that he used to put a tin can with both lids taken off around the young tomato and pepper plants and if I knew why, I’d long since forgotten. Of course, those memories all came back when I discovered that it was cutworms that were destroying my plants. Lucky, a friend told me that when he plants his tomatoes, he slips a plastic knife (there’s always plenty of them leftover from the pack of plasticware) along the stem of the plant and pushes it deep enough that is runs along the part of the stem that’s underground. Well, it worked ! And I never had cutworm problems again - until recently.
This year, we rebuilt our 3 raised beds filling them with the old dirt, some new black dirt from a local landscape company, bags of composted manure, and compost from my compost bin. All my tomatoes, peppers, peas and beans are planted and everything was looking great and since I’ve used raised beds, I’ve never had a cutworm problem. But a week or so later when I went out to check on things, one of the tomatillo plants was cut at the soil level laying wilted on the ground. Cutworms! I found the little critter and quickly smashed him with my shoe and then I quickly got my plastic knives and placed them along all the other plants. So why cutworms now after many years of using raised beds and never having this problem?
Well, lets first look at what a cutworm is. They are moth larvae that hide under plant debris or soil during the day, coming out in the dark to feed on plants. A larva typically attacks the first part of the plant it encounters, namely the stem, often of a seedling, and consequently cuts it down; hence the name cutworm. They need to wrap themselves around the stem to chew through and that’s where the plastic knives come in. Those knives prevent the cutworm from wrapping enough of themselves around the stem to do any damage. They are typically only an inch or so long and when found, they will curl themselves into a C shape. Spring is when they are most active and they feed in the evening or at night on the tender stems of newly planted plants. Their activity slows way down after late spring. Once they transform to the adult moth stage, the moth causes no damage to plants.
So back to my dilemma - why do I have cutworms now when I’ve been cutworm free for so many years? Did they come in with the top soil from the garden center? Or from the transplants I purchased or from one of the bags of composted manure? Well, I guess I’ll never really know though I’m suspecting it was the new top soil. So, I guess as long as I have my plastic knives, hopefully I’ll continue to outsmart those critters. Wish me luck !