How do I protect plants from rabbits in the winter?

Use chicken wire or hardware cloth to make a fence that is 2-3 feet tall around the plants. Bury the bottom to keep them from digging under it.

You may want to go with something that has smaller openings than chicken wire. I have seen a rabbit squeeze through chicken wire.

Hardware cloth mesh wire is significantly stronger, but you will need thick gloves and heavy duty cutters to work with this. It is extremely effective in dealing with rabbits, squirrels, etc. Remember to bury a portion of the wire, for best results.