cabbage

We're having an awful year with cabbage-moth worms this year. They seem to prefer the brussel sprout plant leaves and only move to the broccoli if we are lax about plucking them (overpopulating). We currently subscribe to the pluck/squish control method; we'd prefer not to use pesticides. I'd be interested to hear about any other simple, organic control methods that have been found successful! Many thanks from my brussel sprouts.