from wiki:
how to control cutworms:
Cutworms are usually green, brown, grey, or yellow soft-bodied caterpillars,
often with longitudinal stripes, up to 2.5 cm (1 inch) in length. There are
many variations among the genera. There also are variations in their
biology and control, so the following extension material must be applied
only as appropriate to the region.
In many climates, cutworms will winter under the soil, either as final
instar larvae or as pupae. This affords farmers an opportunity for control.
Winter ploughing will kill many of the pests, and expose many more to
predators. In suitable areas this is a powerful means of control, for
example in grain fields.[1] The same principle permits some domestic
gardeners to kill the caterpillars without the problems associated with the
use of pesticides; the first line of control can be to till the soil some
weeks before planting to destroy any dormant larvae. Also, at any time
during the season, if the population has been reasonably well controlled,
but there are signs of localised cutworm attack, the domestic gardener may
be able to deal with the problem simply by digging the soil and wet foliage
to about 2 inches deep, and killing the caterpillars manually.
Starvation also can be effective when it is practical to keep weeds down
before the growing season, by systematic cultivation. Together with reducing
manure and compost, relying instead on other forms of fertilizer, this can
improve control by discouraging cutworm moths from laying their eggs, and
depriving the larvae of food.[1]
Baits also can be effective where starvation strategies have been applied
reasonably successfully; a sweetened bran mash containing a suitable stomach
poison can be very effective against the small numbers of ssurviving
caterpillars. The mash should be too crumbly and too thinly scattered to
leave any lumps on the ground that domestic animals or desirable wild
animals might otherwise pick up.[1]
Because cutworms attack the first part of the plant they find at night,
plant collars made of aluminum, or even cardboard barriers, can offer
effective protection.[3][4]