Gardener’s friend or foe?

THAT sounds as though it could really be only one thing; cutworms. The larvae or caterpillars of some moths are called cutworms (Agrotis, Amathes, Peridroma, Prodenia spp.) because of the manner in which they cut down young plants as they feed. The adults are night-flying moths which feed on nectar and do no damage.

There are a great many species of cutworms. While they all feed on plants by chewing, they vary as to damage done and host plants preferred.

Cutworms injure plants in four major ways:

■ Solitary surface cutworms cut off young plants at, or above or below, the soil line, sometimes dropping the severed plants into their burrows.

Because most of the plant is not eaten, these cutworms do great damage, attacking and felling new plants nightly.

The black, bronzed, clay-backed and dingy cutworms are in this group.

■ Climbing species, usually the variegated and spotted cutworms, climb the stems of trees, shrubs, vines, and crops and eat the leaves, buds and fruit.

■ Subterranean species, particularly the pale western and glassy cutworms, remain in the soil and feed on roots and underground parts.

■ Army cutworms occur in great numbers, consuming the tops of plants and then “marching” on to other fields.

The moths mate and lay eggs in late summer, beginning the next generation. The moths often seek out grassy or weedy areas to lay their eggs, which are usually deposited on plant stems or in the soil. One female may lay hundreds of eggs. The hatching larvae feed until cold weather and then hide for the winter in a sheltered, dry place. Most cutworms pass the winter as partially grown larvae and are already large, voracious feeders when transplants and seedlings are set out in the fields.

Several cultural practices may offer some degree of control:

Firstly make sure to dig over allotment beds and borders in mid- to late summer to prevent the laying of eggs. Then do the same again in the autumn to expose the larvae Dig over soil in the spring after vegetation has appeared and grown a few inches, then delay seeding to starve the cutworms. Practise crop rotations to avoid a build-up of pests.

Try some physical barriers The construction of ditches and dusty furrows may interrupt army worms.

Place foil or paper wraps or cardboard collars around transplants; extend a few inches into the soil and several inches up the stem.

Other home remedies include catching and placing toads in the garden, wrapping onion stems around the stems of transplants, placing a ring of moist wood ashes around the plants, and placing a toothpick or small nail alongside each transplant stem.

Chemical treatments are also available.

■ Brigid presents the BBC Tees Gardening show on Sundays from 1pm- 2pm. Questions can be answered on the day by e-mailing brigidpress@bbc.co.uk anytime during the week, or texting 07786200995 and phoning 01642-225511 during the show.