I've been using the wildlife friendly slug pellets for several years now and find my slug population is reducing each year. I pick an arbritrary date in early spring that's easy to remember - Ides of March is usual for me but this year spring came early so Vanentine's Day - and go out and sprinkle pellets near all susceptible plants such as hostas, clematis, hemerocallis and daffs and then repeat at regular intervals through spring.
The idea is to get the perishers as they emerge from the soil or hatch from eggs and they then crawl off and die before chomping or breeding. Little and often works well for me.
