Green manure and the vegetable garden
Green Manure For Your Vegetable Garden.
With your vegetable garden it would be a good idea to use green manure over the winter to improve the soil. This well need to be sown in September.
Green manure is by no means a new idea, records indicate that it was used by gardeners and monks as early as the half of the 18th century to increase soil’s fertility.
The term green manure means to sow a short term crop in the autumn or winter such as grass or clover over a bare area of ground after cropping or under an existing crop such as brussel sprouts to protect the soils structure, aid drainage and increase soil fertility.
With climate change bringing higher rain fails in shorter periods of time green manure is a practice that should be used on your vegetable garden over the winter months.
The benefits of a green manure
- Protecting the soil structure – Soil is not designed to be bare nor has it evolved to be bare. On bare soil the action of raindrops smashes the soil particles into individual elements destroying the soil structure preventing the movement of air and earthworms. The top growth and roots from a winter crop helps to prevent this destruction of the soil.
- Increased drainage – green crops help maintain the natural structure of the soil in the winter months protecting the natural channels through the soil and increasing the permeability of the soil to rainwater rather than the rainwater just sheeting of the soil or puddling on the surface.
- Increased fertility of the soil – when a green manure is dug into the soil the green manure releases its nutrients into the soil from the decomposing leaf, stem and root structures. These elements are incorporated into the soil by earthworms which in turn help to improve the soil structure and capability of the soil.
Green manures are sown in the autumn or winter simply by scattering seed and lightly raking into the soil on areas that have been cropped or under winter crops where the soil is bare.
In the late winter or early spring they are simply dug in or covered with a black plastic until they die and start to decompose.
Examples or green manure are
- Grass seed especially ryegrass
- Red clover
- Alfalfa – for longer term green manuring up to two years
- Winter tares