I just this minute saw P. Allen Smith (on weather channel) talk about controlling the slug and snail population from invading the plants. He said that Florida trials showed that when the perennial beds were edged with copper strips sunk into the soil that this method proved very effective. The width of the copper was about 8" deep, length to be determined by the bed of course. He also placed it around individual plants such as hostas, but the depth of the copper was about 4" here. You can also place a band at the bottom of flowering pots and this too deterred the slugs. Apparently copper discharges small amounts of electricity. In order for the copper strips to bend and go round corners, cut into one side of the band all along its length, about one third of the way and approx 3" apart, just as you would do to line a cake tin with greaseproof paper. I hope this makes sense :-) I am definitely going to try this!