I grow a lot of herbs and have been very lucky to have them overwinter by covering lightly with leaves from a maple tree. Vegetable plants get cut off at ground level and then the tops are left to lay on top of the ground until Spring when the ground is cleaned and turned over to start again. I get lots of volunteer tomato plants that often add to the newly planted tomato plants. I've even had this happen with eggplant. You can probably deduct that I am a lazy gardener, but I also use only natural substances on my garden, no insecticides and pesticides.