slug problems

[jann1033]

due to our heavy clay soil i try to add a lot of mulch and so have a serious slug problem...tried diatomacious ( sp) earth,ashes. beer, copper strips type remedies and trapping /picking but still they are everywhere. used to use ducks but we live to close to the road now for that( plus coyotes) we invite birds into the yard....anything else anyone can think of or have used to curb the army? this is for flower and veggies so i don't want to use poisonous things.
thanks