Allotment tales: Tossing a snail into your neighbour's plot is not only antisocial, it's useless

A simple rule of thumb which distinguishes between allotment friends and foes is that pests are usually slow-moving and their predators are faster and more agile.

Slugs and snails are among the most destructive pests I contend with. An allotment is an artificial environment which could have been tailor-made for their happiness. They lurk in damp and shady corners of raised beds, coming out after dark to devour seedlings and young plants. I think they like my strawberries almost as much as I do, but completely blemish-free fruit was never one of my aspirations.

Years ago, I thought my neighbour Rod was mildly eccentric. His garden was overrun with snails which he collected by the bucketload and took to the nearby railway embankment. But his intuition that they needed to be relocated some distance away has been confirmed by Ruth Brooks, the BBC's new amateur scientist of the year. Along with pigeons and hefted sheep, she has proved that snails also have their own built-in homing instinct. Tossing a snail or two into your neighbour's plot is not only a little antisocial but useless. Travelling at a speed of a few centimetres a minute, they can find their way home from a distance of up to 30 metres. To minimise the risk of returning, Mrs Brooks recommends taking them about 100 metres away, to somewhere nice with food and shelter.

Snails can live for more than five years, but it's thought that their life-span is decreasing due to pollution and habitat loss. Whilst this may be welcome news to some, they are part of the food chain. So I am quite relaxed about the occasional encounter with them, though extend a warm welcome to allotment visitors who relish a mollusc supper such as thrushes, toads and hedgehogs.

Snails move along leaving their familiar path of slime. They hibernate in the worst of the winter and can even hibernate in summer if the weather is very dry. They find it difficult to glide over rough surfaces. So time spent protecting the most vulnerable plants with a barrier of porridge oats, crushed egg shells or coffee grounds is definitely worthwhile. Surrounding a young plant with a thin covering of lime is another trick. My local garden centre hands out a recipe for a chemical-free deterrent involving a pungent garlic-flavoured cocktail.

This article was originally published in The Scotsman Magazine on Saturday 23 October 2010.