Mary, having had considerable trouble with cutworms in her gardens, routinely deploys cardboard collars around new plants:
It seems cutworms trundle around until they find an edible plant, chew through the stem and topple the plant, then trundle off without taking another bite. A small cardboard barrier prevents them from sensing the plant: apparently, motivation to climb a short wall hasn’t yet evolved.
Up to this point, Mary applied scissors to tissue boxes, but I proposed an alternative with an adjustable fit to any plant:
A splayed cardboard box rarely lays flat, a condition enforced by a few MDF stops used as clamps.
Come to find out no two tissue boxes have identical dimensions, even boxes from the same brand / retailer, so lay out duplicates of the collar template to match your stockpile.
That was fun!
The SVG image as a GitHub Gist: