How to control slugs without chemicals?

You won't wipe out slugs, but you can keep them off the beds. Remove their hiding places: boards, pots, bags, long grass around the beds, yellow leaves. Then trap them: a damp board, half a grapefruit, or a beer trap (rim a little above the ground so ground beetles don't drown); collect them in the morning and take them away. A couple of evenings with a torch after rain cut their numbers a lot. Water in the morning so the soil dries by night, and plant out sturdy seedlings. Helpers: toads and frogs (they need a pond), ground beetles (log piles), hedgehogs, and on a bigger plot Indian runner ducks. Eggshells, copper tape, grit and bark failed in the Royal Horticultural Society's trials; dry food-grade diatomaceous earth works, but must be renewed after rain. Metaldehyde pellets poison what eats the slugs.