You might need to clarify worms. Do you mean earth worms, which people usually don't want to chase away? Or maybe inchworms or slugs?

Do you mean caterpillars? Possibly cabbage loopers? My preferred method is to pick them off by hand. They do turn into beautiful butterflies, so if they aren't causing TOO MUCH damage, just leave them alone. If they are causing a lot of damage and there are too many to pick off, you can use any number of organic control methods including garlic pepper spray. If you really want to go hardcore, spray with BT (still organic), but be careful, because it will kill any caterpillar that munches on those leaves.

No, not earthworms. I haven't seen them, I just go out in the morning and my mint is all chewed up. I put some Dipel dust on them this evening. I'm going to grind up some eggshells in case it may be slugs but I doubt it. I think I'll go out there with a flashlight and snoop around.