Slugs and snails – loving to hate them

There are 30 or so species of slugs and around 80 species of snail - thankfully only a few of them have found they like your garden

Not top of the list for fascinating wildlife watching, slugs and snails go to the top of another list among gardeners – the one
for the worst pests.

Yet these creatures are a key link in the food chain, food for birds, frogs, newts and toads, and if they are not your favourite wildlife in your garden, they are a natural part of the environment. We just have to manage them – and some, particularly the tiny snails, represent no problem as they prefer rotting vegetation to young plants, and are really very beautiful.

Slugs and snails are found in most parts of Britain, but there are fewer species in the north. There are 30 or so species of slugs and around 80 species of snail in this country, most living in damp habitats such as woodlands. A few have found that they like gardens, especially if there are young plants to
feed on. Snails like lime-rich soils, as they need lime to build up their shells. They are molluscs, part of the large group that includes seashells, but they have evolved to live on land. They still need damp conditions, hiding under logs and stones in daylight hours, particularly if it is dry and sunny. Some slugs burrow deep into the soil.

So, the ones to cross off the pests list are the Brown-lipped Snail (Cepaea nemoralis) with its brown and white whorls, and the White-lipped Snail (C.hortensis). They like dead or rotting vegetation and fungi, not your seedlings.

Now for those that we all love to hate. They include the ubiquitous Garden Snail (Helix aspersa), unmistakable as it is up to 40mm across, with brown flecks on its shell, and the Strawberry Snail (Trichia striolata), much smaller and with a flattened appearance that is up to 14mm diameter.

Among the slugs, the Large Black Slug (Arion ater) which can be up to 200mm, black with an orange stripe along the foot, is really only a problem with seedlings. If you grow plants inside first and plant them out when they are bigger, then there should be less of a problem. The Garden Slug (Arion hortensis) is a burrower, up to 30mm in size, and is identified with a pale stripe down the side of its dark body.

The Grey Field or Netted Slug (Deroceras reticulatum) prefers feeding on the surface. It is grey, with darker flecks and is up to 40mm long. The Keeled or Budapest Slug (Tandonia budapestensis) is also a burrower, up to 60mm, with an orange stripe down the middle of its back.

Slugs and snails are hermaphrodites, having both sets of reproductive organs, able to mate with any other of their species and all can lay eggs that are deposited in loose soil up to six times a year; they are pale, round and jelly-like, with 30 – 80 eggs laid at a time.

Trap slugs and snails if you must, with a commercial trap or jar filled with beer and sunk into the soil, leaving 2cm above so that ground beetles don’t fall in, and partly covered to protect hedgehogs and pets. But first, try our ten tips for living with them.

Ten tips for living with the slugs and snails in your garden

• Grow plants snails and slugs don't like, including grasses, ferns, lavenders and roses, penstemons and sedums – anything strong smelling, hairy and bitter
• Propagate seedlings indoors and plant them out when bigger and less vulnerable
• Grow the vegetables they might go for, in containers and in raised beds surrounded with gravel not grass
• Put cloches over small plants
• Don't leave potatoes too long in the soil – harvest as soon as they are ready
• Place hideaways of logs, rocks and compost for slugs and snails away from plants
• Put copper tape round pots and sheets of matting impregnated with copper that gives them a tiny electric shock
• Lay barriers of egg shells, woodash and/or soot, sharp sand, even human hair that will stop them in their tracks (will dry up their mucus)
• Berried trees and bushes bring in the birds to eat them; a pond will give the garden toads, frogs and newts that will gobble up slugs
• Leave an upturned half grapefruit or wilting cabbage leaves in an area to lure them away from your vegetables