Considered green manure!
Sow outdoors, March-September on any soils to dig in the same year, or sow in August-September to overwinter and dig in the following year. Thinly broadcast the seed over finely-prepared soil, which has already been watered. Dig in after 60-90 days in summer, or anytime before plants set seed and 2-3 weeks before the ground is required. Cut the plants back and allow the foliage to wilt before digging in to a depth of 15-20cm (6-8″). Chop up the foliage with the spade as you dig. Overwintered crops can be dug into the soil in spring. Ensure plants are cut back or dug in before they set seed.