I somewhat doubt there is anything you could plant around the garden to repel woodchucks... especially since they have already discovered the gardens. Wally, you might first want to try something like Safer Animal Repellant spray ("powerful groundhog repellent that contains 3 great-for-repelling-groundhogs ingredients – capsaicin, piperine, and black pepper oil. The combination of these ingredients drives woodchucks away by creating an unpleasant burning sensation."
Read more:
https://pestkill.org/rodents/g...)
Otherwise, I think the exterminator might be your best course of action.
