Gardening > Slimy Pests In Your Garden

Slimy Pests In Your Garden


Snail (Helix aspersa)
Creative Commons
Attribution 2.0

"But how can the casual gardener distinguish friend from foe? This is not always easy, but here is a fairly reliable guide. If an insect can run about actively in the soil it is a friend and is usually hunting. The centipede and roué beetles are a good example. But creatures which cannot run, such as slugs, wire worms and leather-jackets, are enemies and should be treated accordingly."

So wrote Mr. Middleton, gardening writer for the Daily Express in 1939. 

Snails also fit Mr. Middleton's criteria of slow moving visitors to the garden and both slugs and snails are probably among the best know of pests that descend upon back gardens. They can reduce rows of lettuce to ragged stumps in no time at all.

Slugs and snails excrete a slimy substance which leaves a distinctive shiny trail. The slime helps then to move easily and it repels any grit or dirt which they might encounter. This trail also a source of information for other snails and slugs as to the sex of the trail maker, where they are going and what food they are making for. A slug or snail will use the trail made by other slugs and snails to save the energy needed to create its own trail (and then the blighters can put more effort into eating your lettuces!)

Slugs and snails hide during the day in moist, dark places, such as old flower pots and under overgrown bushes. Slugs tend to spend a lot of time below the soil. During the winter both slugs and snails will go into semi-hibernation if the weather is extremely cold and they only come out to eat when the temperature rises. Both are hermaphrodites and lay white translucent eggs on the soil. When the young hatch out they feed first on any waste organic matter which may be close at hand and then as they grow they progress to precious vegetables and plants Usually they come out when it is dark and feed on soft leaved plants. They will reek damage on ground level or further up the plant wiping out months of hard work and anticipation in the course of one night.


Black Slug (Arion ater)
GNU Free Documentation

The very best defence against slugs and snails is a clean garden. Clear up old, damp leaves, cut back overhanging branches and keep patios swept. Make sure that any stored plant pots are clean and dry and throw away old, half empty bags of compost. If you are lucky enough to have thrushes in your garden, rest assured that they will decimate the snail population. You could try to encourage thrushes by buying suitable bird food. Hedgehogs will help to keep the number of slugs down so again suitable hedgehog friendly food and habitat would help.

It isn't a good idea to use slug pellets because they can be dangerous not only to humans, dogs and cats but also to the thrushes and hedgehogs which might eat the slugs and snails. Copper slug tape is very effective as are slug traps. Another good way to rid the garden of slugs and snails is to simply pick them off the plants at night (use a torch!) and to then dispose of them in a way you feel happy with. Always check underneath flower pots and under the rims because slugs and snails can lurk ready to come out at night. Gravel can act as a deterrent since it forms a sharp, inhospitable surface for gastropods. Old gardening books often advised laying a few cabbage, lettuce leaves on the garden path or patio overnight to attract the slugs and snails away from the crops. The half eaten leaves can be removed the next morning complete with some of the pests if you are lucky.

No normal garden is ever going to 100% pest free - indeed that is not the aim of organic gardening. With a little care and effort a good balance can be reached. There is no point having a nervous breakdown if a lettuce or two are eaten or invaded but it is quite possible to create a garden which is less hospitable to slugs and snails thus ensuring that the majority of your crop makes it to the table crisp, juicy and in tact!

See also:
The Green Chronicle Online Shop
Gardens Alive (external link)
BBC Pest Advice (external link)