Sow green manure to cover bare soil in winter

Green manure is a crop you grow to protect and feed the soil, not to eat. Sown on bare beds in early autumn, it covers the soil through winter, stops rain washing it away, and keeps weeds out. In spring you cut it down, and it rots back into the bed. I sow green manure on every bed that would otherwise stand empty.

Which green manure to sow #

Crop	When to sow	What it does
Grazing rye	Early to mid autumn	Grows in cold weather, and its roots open up heavy soil
Field beans	Autumn	Add nitrogen to the soil, and the young tops are edible
Crimson clover	Late summer	Adds nitrogen, and flowers for bees if left into spring
Phacelia	Late summer	Fast cover, and loved by bees if it flowers

Field beans and clover belong to the pea family, so they add nitrogen to the soil through their roots. Do not follow them with more peas or beans, to keep pea and bean diseases from building up.

How to sow it #

Rake the bed level, scatter the seed thinly, and rake it in. Water it if the soil is dry. That is all.

Cutting it down in spring #

Cut it down a few weeks before you plan to plant. Leave the cut tops on the surface to rot, or cover them with leaf mould or compost. On a no-dig bed you can lay cardboard over the top instead of digging it in.

Green manure is also a good use of the bed where you lift potatoes, before you plant garlic in late autumn. And in a hot summer, a covered bed loses less water, as I wrote in my letter on the dry spell.

The entry on green manure at Wikipedia lists more crops and how they work.