Something is eating my tomato stems-containers

[greenhousekendra]

Please help. This is my second year growing in home made earth box containers. This year I noticed that something is eating the main stems of my tomato plants. Since they are in containers, where do I put the bug killer and what do I use. Thanks!

[dice]

Perhaps this thread belongs in the "Common Garden Diseases
and Pests" forum?

A picture might help people guess what the problem is.
(I do not know what pests in Kansas might crawl up the sides
of a container and chew on plant stems. What kind of soil
is in the containers? Bagged potting mix? Out here, in the
ground, I might guess cutworms. Are there little holes in the
stems, like from borers of some kind, or does it look like just
random chewing?)