Nourish your soil with green manures


Lee Bestall
22nd October 2020

With the rapid rise in the popularity of no-dig approaches to gardening, there is also a growing interest in the use of green-manures to help protect and nourish soils that may otherwise be left bare over winter.

The term “green manures” is just a fancy term for quick-growing plants that protect and nourish the soil. If you’ve got a veg garden, allotment, or just some bare flower beds that you are waiting to plant in spring, now is your last chance to sow a green manure to help improve and protect the soil over winter.

Green manures work in a number of ways:

  • They provide a protective cover from the harsh winter weather
  • The roots of green manures hold the soil together and help prevent it from losing structure
  • Covering the soil helps smother out weeds
  • The plants help feed the soil organisms that are vital to good soil health
  • The growing plants take up and lock in nutrients that would have been washed from the soil with the winter rain
  • Green manures in the pea family are nitrogen fixing “legumes”; these take nitrogen from the atmosphere and fix it in their roots, releasing it back into the soil when they break down

Sow your green manure seeds onto the bare soil, and lightly rake in. At least two weeks before you want to sow or plant into the bed with the new year’s crop, cut down the green manure. Then either dig it in or hoe through the roots and leave it all to break down and feed the soil. If you leave it a bit late, make sure you cut them down before they flower because you don’t want them to set seed and become a weed in the garden.

November is the latest you can sow a winter green manure. Either buy them at a garden centre in the green manure section of the seed racks, or online with a reputable seed retailer. There are many other types of green manure that can be sown from spring through to autumn, but these are your main options for a November sowing;

  • Grazing rye (Secale cereale) is an annual grass closely related to barley and wheat. Like most grasses, the fine roots are great for improving soil structure and preventing erosion.
  • Winter field bean (Vicia faba) is more commonly known in the culinary sense as the good old broad bean. This is an annual that will bring nitrogen into your soil, and does well on heavy clay soils.
  • Forage Pea (Pisum sativum) also generally known as garden peas, are also nitrogen-fixing annuals, used to help prevent nutrients washing from the soil over winter. 

This winter, don’t watch your soil wash away in the rains, grow something that will nourish your plot and give you some green hope to see you through to spring.

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The Author

Lee Bestall

Lee Bestall

As a horticulturalist and garden designer, I'll be guiding you through the seasons ahead, sharing tips, successes and failures and exploring some of the new and inventive products on the market.

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