Cover Crops & Green Manures

Cover crops and green manures help the soil but are not broadly considered a cash crop, unless they can be grazed prior to establishing the next crop. Though there is a cost to establishing these beneficial crops, if you make the right choice they will repay any outlay, bringing many benefits to your farm. Here are just a few:


They capture energy in the form of sunlight that would otherwise hit bare soil and be wasted. Green manure can be seen as a nutrient store for use at a later time. 


Green manures provide a habitat and food for predators and pollinators as well as providing a habitat for the soil organisms that we don’t see.


Cover crops protect the soil from damage including: drying, which can cause wind erosion; rain damage, that can lead to nutrient leaching and increased disease from rainsplash and run-off; and compaction caused by both vehicle and foot traffic (human or livestock), the effects of which can be eased through added roots and organic matter.

Weed control 

A good cover crop will smother weeds, though managing it can create its own challenges.

Improve the workability of soils for future.

Cover crops are usually divided into three broad categories:

Long Term

In many systems, this is the fertility building phase. At bare minimum, a nitrogen fixing plant and a bulky grass are needed. Traditionally a grass clover mix is used, though increasingly innovative seed companies are developing specific mixes for different soils and systems. Cotswold Grass Seeds are a good example of a business that can help you find the right fertility building seed mix for your farm.

Catch Crops

These are quick growing annual or ephemeral plants that can bulk up to smother weeds and capture soluble nutrients in the soil before they are lost through leaching. Mustard is commonly used as it is cheap and grows well in our climate, though phacelia, buckwheat and fenugreek also offer a good alternative.


Short growing legumes like white clover or yellow trefoil are often used in horticulture, with red also a possibility in arable crops. The key to making this work is timing: the undersown crop should not be established too early, so that it would compete and affect yield, nor too late, so that it would be smothered by the cash crop. 

Sort Out Your Soil

Cotswold Seeds


View Guide

Nathan Richards: Fertility is the focus

Soil Association

Simon Gardner: Disturbing the Soil Less and Less


Author: Ben Raskin


Head of Horticulture

Ben can help individual members with horticultural technical, marketing, supply chain and networking queries. He also holds specialist knowledge and experience which includes Agroforestry,  Community Supported Agriculture, starting up new horticultural businesses and Biochar. Ben has been working in horticulture for more than 20 years and has been with the Soil Association since 2006. His own experience includes; running a walled garden in Sussex supplying a Michelin starred restaurant, working for Garden Organic at their gardens in Kent. Ben also set up and ran the 10 acre horticultural production at Daylesford Organic Farm, before moving to the Welsh College of Horticulture as commercial manager. He is currently project managing a 200 acre agroforestry planting at Helen’s Browning Farm in Wiltshire.

On top of this Ben has written a few gardening books, mainly for kids.

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