I've had my Can-O-Worms bin in a shaded, sheltered outside corner for 11 years. Whenever I find a plant that's having problems, I give it a trowel-full of worm castings and it perks right up. I use a diluted solution for my container plants, and this year put a dollop at the bottom of each of the holes I dug for my tomatoes (no fruit yet, but the plants look fabulous).
In the winter we get temps down to the twenties, and the worm activity definitely slows down. But as soon as it gets over 50 degrees, they get busy again. Mine get all my coffee grounds and filters, along with other kitchen scraps. I think the coffee helps keep Argentine ants out.
I often dump a couple of big scoops into my regular compost (mostly yard clippings and shredded paper) and the worms seem perfectly happy to work on that material, too.
I used to quite a bit on organic fertilizers-----not any more!
