It is said that few legumes match Vicia villosa or “hairy vetch” for spring residue production or nitrogen contribution. Widely adapted and winter hardy through Hardiness Zone 4 and into Zone 3 (with snow cover), hairy vetch is a top nitrogen provider.
The cover grows slowly in fall, but root development continues over winter. Growth quickens in spring, when hairy vetch becomes a sprawling vine up to 12 feet long. Height rarely exceeds 3 feet. Its abundant, viney vegetation can be a benefit and a challenge. The stand smothers spring weeds, however, and can help you replace all or most nitrogen fertilizer needs for late-planted crops.
Hairy vetch ahead of no-till corn was also the preferred option for risk averse farmers in a three-year Maryland study that also included fallow and winter wheat ahead of the corn. The vetch-corn system maintained its economic advantage when the cost of vetch was projected at maximum historic levels, fertilizer N price was decreased, and the herbicide cost to control future volunteer vetch was factored in. 
Soil: Any, widely adaptable
Climate: Any, but not winter hardy north of New Jersey
Per acre: 30 pounds
Per 1000 square feet: 1 pound
Seed Depth: 1/2 inch
Sow: Fall or Spring
Turn under: Spring or Fall
“The earth neither grows old or wears out if it is dunged.”
~ Columella, circa 45 A.D.
- Hanson, J. C. et al. 1993. Profitability of no-tillage corn following a hairy vetch cover crop. J. Prod. Ag. 6:432-436.