This is from Growweddeasy.com:
Slugs/Snails
The common slug is too common a pest to even need much of an introduction. Slugs attack a wide range of plants, causing anything from slight damage to death.
Unfortunately, these annoying pests attack leaves AND buds, and they can do a surprising amount of damage in a short time, so you want to watch out for them and get rid of them quickly.
They often stay hidden, attacking your plants at night, so stay vigilent for slug and snail damage!
Solution: There is no foolproof method for eradicating slugs.
All one can hope for is to reduce their numbers and protect plants when they're at a vulnerable stage.
Toads, frogs, and beetles eat slugs and are worth encouraging in your garden. One of the best ways of dealing with slugs is to use physical barriers.
Place plastic bottle cloches around plants, or sprinkle circles of lime, eggshells,
Diatomaceous Earth, or sawdust around plants.
Slugs are attracted to saucers, orange rinds, and plastic pots of milk or beer (they drown themselves in ecstasy).
How to Make Beer Trap for Slugs and Snails: mix flour with some stale beer and use it to fill a shallow container. Place in garden with the rim 1 or 2 cm above the ground so that slugs and snails can climb in. Substitute beer for wine, sugar water, juice, or water mixed with yeast.
BE WARNED, the trap will fill up quickly so come back often to empty.
To be sure you're keeping your slimy slug population under control; collect them by hand at night or on damp days. Try collecting them under a tile or wet cardboard, and squash all eggs you find while digging. Placing a saucer of salt is another method that will kill snails and slugs.