Winter Hairy Vetch

Winter hairy vetch is a vigorous annual legume crop used for fixing nitrogen, biomass production and enhancing organic matter. It’s an excellent choice for green manure as its low carbon to nitrogen ratio (C:N) allows for quick plant decay and even quicker capture of organic material and nutrients in the soil profile. Hairy vetch tends to be very tolerant of variable soil conditions, including low fertility environments. Hairy vetch will overwinter in many areas of the country (USDA Zone 3-4) withstanding temperatures down to -25 to -30°F, especially where snow is likely.

• Strong nitrogen fixing and high biomass potential
• Great to recharge soils during winter by reducing runoff (more water enters the soil profile
through pores created by the vetch residue)
• Phosphorus scavenger
• Heavy mulch layer provides excellent weed suppression and erosion prevention
• Excellent option to plant with cereal grain (helps with spring control too)

• Slow to establish
• Prefers soil pH 5.5 – 7.5
• Little forage value (seeds and vegetation can be harmful if not managed)
• Glyphosate alone doesn’t work well for control (close mowing or light disc will offer spring control)
• Without proper management, it has potential to become weed (high hard seed %)
• Keep off poorly drained sites to aid in spring termination and water conservation
• Research shows potential correlation between hairy vetch and increased soybean cyst nematode/root knot nematode populations

Winter Peas

Winter Peas are a rapid, low growing annual legume used across the country as a legume fixing cover crop and/or a quickly decomposing green manure crop. The forage value of winter peas, along with their overall management are benefited when planted alongside a cereal grain.

• Strong nitrogen fixer and very high biomass potential
• Quick growth good for weed suppression
• Plant 6-8 weeks before first frost to maximize growth and nitrogen production (bud stage or after)
• Hardy to USDA Zone 6 (-5 to -10° F)
• Spring Peas planted in fall (SF 125 & SF 140) need 60-90 days to maximize growth

• Ideal soil pH 6.0 – 7.0
• Not the best option for nutrient sequester and/or breaking up compaction
• Large seed size makes broadcast applications more difficult
• Mowing or forage harvest in spring will terminate crops

Sunn Hemp

Sunn hemp is a warm season legume, upright and quick in its growth habit. Sunn hemp needs 60° F soil temps before it can planted and will kill at the first signs of frost. Higher seeding rates of sunn hemp will help with weed suppression.
• Produces significant amounts of nitrogen in 60 days depending on conditions
• Tolerant of dry conditions and low fertility
• Can add up to 5,000+ lbs. of biomass per acre in 7-8 weeks
• Research has shown levels of nematode suppression (root knot, borrowing)

• Prefers soil pH levels above 6.0 (6.0 – 7.0)
• Kills at first frost, or control by mowing or herbicide at first flower for maximum benefit
• Residue (green manure) should be incorporated while still green
• In far southern areas (below 28° latitude), sunn hemp will produce seed which can be toxic to livestock