You might be able to feed your worms with garden trimmings. Have never done it but as long as you have stuff without herbicides or pesticides, I can't see how green or brown leaves would hurt. My dad used to harvest nightcrawlers from his yard waste compost pile. As for harvesting compost, I expose the compost to light like Dave but I do it on a big plastic bag on the garage floor. There's enough light in there that a spotlight wasn't needed. I dump all 4 of my worm tower bins in a pile in the middle of the plastic. Wait 10 or 15 minutes for the worms to migrate further down into the pile and scoop off the top few inches. Repeat this as often as you need to. I used to sift through the worms to get to compost but this new (to me) method yielded almost all of the compost in the bins. Do save a little of it to put back into the bins with fresh bedding and food.
