Cover cropping is a method of managing soil health, it fixes nitrogen in a biologically active form, adds biomass to the soil, reduces pests and weeds. You alternate your vegetable crops, with often in the winter, vetch and grains. In the spring right when it starts to flower you cut it up and till it into the soil. It’s all around a good agricultural practice. This is just my second year cover cropping my community garden plot. The first five years I was too tempted by the mild California weather, I planted vegetables year round. Each year, despite adding compost, my plants got smaller and smaller. My garden mates who cover cropped got these huge bumper crops that made me jealous (and kinda amazed). So, now I cover crop. This is some of the blooming Vicia faba, its really very beautiful.
Bell Bean
(http://ucanr.org/sites/asi/db/covercrops.cfm?crop_id=5)
Walkabout 