Benefits

• Cover crops such as annual ryegrass, clover or hairy vetch reduce soil erosion by keeping the soil covered during harsh winter weather. These crops also improve the texture of the soil and add nitrogen as they break down. Annual ryegrass has alleopathic properties that suppress weed seed germination. Leguminous crops such as clover and hairy vetch are particularly beneficial for fixating nitrogen in the soil. Consider planting a mixture of annual ryegrass and hairy vetch or Austrian winter pea.
  
  

Potential Drawbacks

• Ryegrass is somewhat more difficult to kill in the spring than other crops. If allowed to go to seed, it may interfere with vegetable crops. Its alleopathic properties suppress not only weed seeds but also vegetable seeds, possibly inhibiting germination.
  
  

Use

• Plant annual ryegrass in September in most regions so it has time to sprout before freezing temperatures. It keeps the ground covered all winter, preventing soil erosion. Till rye under in early spring before it goes to seed and at least four weeks before planting the first crop. Till it with a rototiller or a spade to a depth of 4 to 8 inches. Tilling annual ryegrass several weeks before planting gives the grass time to decompose, which reduces the risk of an alleopathic reaction with vegetable seeds.
  
  

Seeding Rate

• Hand broadcast 2 1/2 to 3 1/2 lbs. of seed per 1,000 square feet of vegetable garden soil. Rake the area to incorporate the seed or cover it loosely with 1/2 to 1 inch of soil. Keep the soil evenly moist until the plants stand 2 inches high. Plant cover crops for three or four years to see noticeable improvements in soil texture.