Green manures: a lot more than fertilizer!

A green manure is a ground-covering culture with soft stem. It is not harvested as its purpose is to feed the soil. In making the « soil work », this cover enriches the soil and avoids for a non-cultivated plot of land to be invaded by weeds.

Mustard in flowers

Phacelia in blossom in an orchard

Multiple benefits

A green manure enriches the soil as the culture will be buried in situ and will decompose, often very quickly, which will enrich the soil. In sticky grounds, green fertilizer also improves the soil' structure and lighten the soil. Furthermore, the flowers are pollinated by honey producing bees. A green fertilizer is an excellent way of preparing the vegetable plot's soil. Clever!

Sowing

All you have to do is to spread the seeds by hand on a raked, weeded soil as if you were to sow grass seeds for example. Sow approximately 1g of seeds for 1m2. Do not cover the seeds. Let them fend for themselves, without packing them down or even water them. A green manure must always establish by itself to give you the best result.

Once risen, let them grow

Green manure usually does not need any help. Nevertheless, if the weather is dry, it will form a thin, not very dense cover which is going to encourage weeds to settle in. In this case, it is best to water it a little. Let the culture develop until it starts blossoming.

Shredding of green manure (Nasturtiums)

Cut in situ

When the stems start to wither, you must shred the culture. If it is a small area, do it with a garden spade or a strimmer. For a larger surface (more than 50 m²), a lawn-mower is more suitable. Set it on the highest cutting level and use it to shred the stems.

Digging of green manure (Nasturtiums)

Plough it and it's done!

Return the soil to bury the crushed stems underneath. If all of it is not totally buried, do not worry. The stems will decompose all the same if they have been properly chopped.

The right period

There is not in theory a preferential period to cultivate a green manure. Each usable plant to produce a green fertilizer has its own preferences: depending on the period, you can choose one of them rather than another.

Which variety to choose?

The classics green manures are the Mustard and the Phacelia, pretty plant with blue flowers. There are a lot more to choose from like Cereals, Rape, Flax, Red Clover (Trifolium Pratense) or again Buckwheat (also called 'black wheat'). They all have different sowing and burying periods. The range allows you to use them all year round!

Sowing Calendar of green manures