Hopefully this is a quick question. We're in zone 7a (Virginia) and have had a surprisingly warm fall up until this week. I have relatively new hugelkultur beds with a variety of wood, leaf, soil layers but would very much like to do a cover crop this winter to add some more organic matter and nitrogen to the soil given the newish wood within the mounds will take another year or so to start giving off nitrogen. All that said, is it too late to plant a cover crop in zone 7a and what plants would you recommend that would last well into the fall and/or through the winter. Thanks in advance for any responses!