Slug

Slugs are amongst the most troublesome of pests as they have a very varied appetite. There are a number of control methods from chemicals to more organic practices.

Identifying features
Leaves of plans show curved 'bit' marks in them, usually at the edges, but often in the body of the leaf too. Seedlings, stems and roots are also targeted. Slime trails are often left.

Treatment
None.

Prevention
A number of preventative methods are available:

Metaldehyde pellets
The most effective use of metaldehyde pellets is to put pellets down on a humid evening during warm weather. Slugs are more active during the night in hot weather when they will be attracted by the bait ingredient (usually yeast among other things) in the pellets. By morning the slugs will have been dehydrated by the poison and be unable to move into shelter. The dry weather will finish the process. Effects are lessened by cooler or wetter conditions, but pellets will still slow slugs down.

Beer or milk
Smooth glass or plastic containers, sunk into the soil and filled with beer or milk, certainly trap slugs. However there are problems. Never, for instance, sink the containers with their rims flush with the soil level. If you do, you will drown ground beetles that are important pest (including slug) controllers. The rims should be 1-2 cm above the soil's surface; slugs can crawl up and over quite easily. For this method to be an effective control, you need an awful lot of beer traps - at the very least one every meter in every direction - and an awful lot of beer or milk. The liquid must be replenished every few days, which can be quite a task. However, on a small scale, to protect a group of choice plants, the technique can work.

Sharp barrier
A number of different materials can be used to surround plants with the intention of deterring slugs. Most, like sand, ashes, broken eggshells and soot are physically difficult for slugs to get across either through being scratchy and sharp or by drying up the mucous glands that are necessary for their movement. There may sometimes be a chemically repellent effect as, for instance, in the case of ashes.

Coffee grounds are both abrasive and acidic and can act as a barrier to slugs. They also contain a high percentage of nitrogen as well as magnesium, calcium, potassium and other trace minerals.