Yep seriously, that’s what its called! It’s the name given to a crop which you grow, and then deliberately turn into the soil before you harvest anything, to add nutrients back into the earth. Some crops, especially types like alfalfa, clover, peas, beans, and lentils are particularly clever at pulling nitrogen out of the air and depositing it into the soil, and its one of the best ways to take advantage of the cooler dormant growing season to get things prepared for spring.
I picked up this green manure seed mix from a Canberra Organic Growers Society session I attended a while back. It’s got all sorts of goodies in it. I also sprinkled a good couple of handfuls of wood ash from the fireplace to boost the potassium levels – a tip I caught on the last episode of Gardening Australia.