Slugging It Out

Conchologists--scientists who study slugs and snails--extol their subjects. Gardeners are prone to use more earthy language in their descriptions. There are few places where humans reside not also occupied by terrestrial gastropods. The deserts, no--also not in the High Arctic and Antarctica. Oh yes, and the International Space Station. Elsewhere on the planet, much to the delight of the mollusks, gardens have been established. So how, particularly in these times of environmental concerns, can we control these slimy subjects without resorting to chemicals? Alas, many of the ways commonly suggested have proven to be not particularly effective.

One of the most popular, frequently promoted in this venue, is trapping in shallow dishes of beer. The mollusks are attracted to the stuff the theory goes, climb in, drink and drown happy. Some have also claimed that modern mass-produced beer is enough to kill anything. Recent research tends to indicate that while it works, it is effective for very limited distances. Belts of ground limestone, encircling entire gardens or simply individual valued plants, have also been recommended. The idea is that the scratchy, alkaline surface inhibits the creatures' mode of locomotion. Again, experimentation has proved this to be questionable. Likewise, dried and crushed eggshells have been suggested. The late New Zealand gardener Virgil Evetts apparently tested these and found them ineffective, according to NZ Gardener columnist Barbara Smith. She also throws doubt on coffee grounds and even copper strips. The latter have received praise elsewhere from Hosta fanciers whose plants are frequently nothing more than salad bars to slugs and snails. Smith writes: "My proven method is time-consuming but effective. Go snail hunting regularly at night with a torch and a bucket of warm water."