I didn't realize that true armyworms were a problem that far north or at least not a consistent problem other than the random moth migration. They are normally considered a southern zones crop pest.

And using barriers as a control has little supporting research. For cutworms, sure, but not armyworms. Most of the controls for them are directed at the foliage and the early stage instar larvae since they do the majority of the damage. So pesticide-oriented, either synthetic or organic. Little of the research I have read seems to indicate that stem protection is the focus or that stem barriers is effective unlike with cutworms.

So I'm really curious to see what others have to say about the effect of stem barriers.

Dave

Thanks, Dave, I probably mixed them together, but yes,ones I am fighting are cut worms. I thought that army worms is a one type of cut worms called that way by the color, and mine are sure "army" color) So how high the barrier should be?

I actually found a source of my confusion:

"Some cutworms, e.g. black, bronzed, and army cutworms, can be very injurious," from here

Different moths, different life cycles, different coloring, and different damage. Cutworms go for the stem at ground level, encircle it, and literally cut the main stem. So height isn't so much the concern as is direct contact with the stem so they can't wrap around it.

Personally I use the disposable plastic soda straws stuck right up against the stem itself. I don't cut them in half cause I'm lazy at that so they are a good 10" or so with about 3" below ground. You could cut them in half and it would still be long enough I think. Some use the old 10 penny nails that are approx 6" long, some use stick or twigs. Some advocate toilet paper tubes cut in half but IME the worm can get inside them and still damage the plant.

Dave

OK, my plastic tubes help as well, never lost one cabbage due to cutworms since started to use them. But I sift the soil in the planting hole before I plant and install the tube. I guess they just do not pass that underground part. But can they actually crawl up the plastic? Or stand up like some caterpillars do to catch the top of the barrier if it is not high enough?