Buckwheat

For summer green manure. Sow in late May through July and till in about a month later when flowering has begun. Non-legume broad leaf does not fix Nitrogen, but is one of the best hot weather cover crops because of its ability to produce organic matter and smother summer weeds (Canada Thistle, Quack grass, Nutgrass, etc.) quickly. Also accumulates insoluble phosphorus and, when turned under, releases it to the soil in plant-available form. It attracts beneficial insects, and grows to maturity in 30-45 days, so 2 to 3 plantings can be sown in one summer. Annual, will winter kill. Mature height varies with soil quality, from 8″ to 3′.