are there any plants that will grow in heavily shaded woods?

ferns?

Use a chainsaw and thin the canopy by taking out a few trees and use a clover blend. If you are in the dry part of the country it will do well with 4-6 hour of sun.

Its all going to depend on how much shade you are talking about. If it is a thick canopy and you just want to plant an old road or something then I don't think you are going to have much luck. An excavator and dozer will be your friend.