Hairy Vetch Cover Crop
This annual legume has been shown to provide excellent nitrogen fixing and is more resistant to frost than any other. Sow in late summer to establish a stand before the ground freezes, and it will survive ordinary winters in the North to re-grow vigorously next spring. Turn in a few weeks before spring planting. It benefits from having a companion grain like rye or oats planted with it to protect it through the winter and provide support for vines in the spring. Unless you have grown vetch in the last 3 years in your garden, you will need an inoculant if you want it to fix nitrogen. A versatile green manure, it tolerates acid soils, low fertility, and shade, and can fix over 100 lbs. nitrogen per acre. Grows about 2 feet tall. Sow 1 lb. per 1,000 sq. ft.