Controlling damage done to yard and garden plants by slugs and snails can be a real problem for organic gardeners. These common garden pests like to eat tender seedlings and the growing tips of plants, and can wipe out a garden bed in a few nights. There are chemicals and poisons sold to control slugs and snails, but people who garden organically usually don't want to use these products. I've compiled a few non-toxic (at least to humans and pets) methods of getting rid of these critters.
Picking the slugs and snails is very effective. In the early morning while the dew is still on the garden, the gardener can simply go out and manually pick the slimeballs out of the garden and off of the plants. A word of warning here...slug slime does not wash off easily. If you're going to use your hands, be prepared to scrub for awhile. I pay the neighborhood kids to gather the slugs and snails from my garden. At ten cents a critter, the kids make some money, and I rid my garden of slimy pests.
Probably the most well known non toxic method of getting rid of slugs is the slug trap. This is a container that the slug or snail crawls into and drowns. These can be bought, or can be made by burying a shallow bowl up to the rim in the dirt and filling it with beer. The silly slugs crawl into the bowl, get drunk, and die happy.
The final method of slug/snail control that I'm going to talk about is using a barrier. Slugs and snails don't like to crawl over certain things. If you can put those undesired items in the slugs path, he'll go elsewhere. The most effective barriers that I've found are crushed eggshells, copper wire and diatomaceous earth. The eggshells and earth are rough and unpleasant or even fatal for a snail to crawl over. The copper wire give off an electrical charge that repels the creatures i believe. Both the wire and the earth can be bought wherever organic garden supplies are sold.
There are a bunch of other things that people use to help reduce damage to garden crops and flower beds from slugs and snails, but these are the methods that I've used with some success.