I have a bunch of potted fruit trees and bushes in my backyard orchard, and I need to move them into my unheated garage to help them get through the winter cold. However, my garage has no windows, and rarely gets opened, so the plants would get basically no light at all during the winter.

Is this okay? Do plants need light throughout their winter dormancy?

If so, can I just put a couple cheap lights in there with them, or would they need a more high powered lighting system?

Thanks!