Sow these Green Manure Seeds - Field Beans & Mustard in seed trays to give them all they need. Plant out into final position when big enough and watch them yield amazing crops of tasty, fresh and healthy produce or sow directly in the ground. They can be cut once and allowed to re-grow to produce second flush of foliage before digging in.
Dig in any time up to flowering. Fixes Nitrogen, it will not tolerate drought conditions and prefers heavier/clay soil.