Green fertilizer : what is it for ? Which plants ? When to sow ?

Star of permaculture, green manure or EV should be sown everywhere when a plot is not cultivated. Amateur gardeners are also beginning to take an interest in it and they are right because green manure is virtuous at different levels. Let’s take a closer look.

What is a green manure (VE)?

We call green manure the plants sown for a intermediate period so as not to leave the ground bare. Not meant to be harvested, this crop is then mowed or plowed into the soil to fertilize and improve it without the need for chemical fertilizers. This is a technique that is not new and it is increasingly used by organic market gardeners.

What is the use of green manure?

If he wants to have a beautiful garden and enjoy abundant harvests without having to deal in all directions with more than suspicious products, the gardener must meet many challenges throughout the year. He therefore has every interest in opting for green manure because his multiple benefits hoist him among the best cultivation methods.

Wind and rain or irrigation water are responsible for the erosion of bare soil. Sowing a green manure is therefore useful for fight against erosion. EV is a ground cover whose root system leads to small cracks facilitating the loosening of the soil, the exchange of water and air with the surface of the soil, and also favoring the penetration of water in depth. We can therefore say that green manure preserves the soil in an ecological way. But these are not the only assets, far from it. We can also note that a green manure:

  • Boosts the biological activity of soils by feeding earthworms and other organisms that transform organic matter into fertilizers that plants use directly but also into humus that can be used later.
  • Improves the structure of the soil in the garden, certain plants that constitute a green manure are even capable of stabilizing the structure of loose soil. This improvement is of course linked to the duration of vegetation of the green manure.
  • Reduces the loss of organic and mineral particles on the surface.
  • Preserves or even increases soil fertility.
  • Allows to considerably limit the purchase of nitrogenous fertilizers because it replaces them at least partially.
  • Makes the soil less vulnerable to pathogens.
  • Attracts beneficial insects from the garden, especially when the EV is in flower.
  • Effectively helps to control the proliferation of weeds. If its density is sufficient, green manure effectively deprives local grasses (wild plants) of light, water, nutrients, and considerably slows down the propagation of their seeds.

About the disadvantages of green manures, they are few compared to their advantages. It can be noted that they are likely to encourage the development of certain garden pests such as snails and slugs. They can also be blamed for favoring the presence of Diptera larvae, in particular crane flies. Fortunately, insectivorous birds are fond of it and also consume a lot of gastropods.

In any case, we can say thatgreen manure is never harmful. We can therefore sow it almost with our eyes closed.

Which plants to sow to obtain a green manure?

The choice of plants to make his green manure is extremely wide, which allows each gardener great freedom since he can select plants in the families that lend themselves best to it, as is the case with legumes, grasses or even crucifers…

  • vetch,
  • winter peas,
  • crimson clover,
  • white clover,
  • berseem clover,
  • Sainfoin,
  • Phacelia,
  • white mustard,
  • Buckwheat,
  • fodder radish,
  • Mélilot,
  • Rapeseed,
  • fever oil,
  • Shuttle bus,
  • Fenugreek,
  • Hemp,
  • oats,
  • Sorgho,
  • Ray-grass,
  • Borage,
  • Cosmos,
  • Nasturtium,
  • Worry,
  • Alysse…

This list is not exhaustive. You can opt for a green manure made up of a single species, but it is better to combine several plants from different families to obtain a green manure, which in this case is called meslin. Combined with each other, species handle more problems than when used alone.

All that’s left is to mowing green manure just after flowering, before the seeds are formed, or elseto tear out if you want to plant vegetables there. But we leave it in place after mowing it if no cultivation is planned immediately.

When to sow green manure?

You can sow an EV at the very beginning of the spring or in fall, i.e. before the main crop or just after. Of course, we anticipate so that the green manure no longer occupies the plot intended to accommodate seedlings and young plants from the vegetable garden, that goes without saying.

By logic, it is important to take into account the specificities of the plants that one wishes to use for these purposes to sow them at the right time, in a soil whose quality suits them. Of course, frost-resistant plants are sown in spring and the hardiest in autumn. For example, between March and May, we sow mustard, sainfoin or even phacelia, while once September is over, we concentrate more on sowing crimson clover, rye which, like many still others will withstand the harshness of winter without any problem and will quickly resume vegetation after the off-season. Finally, when a plot is completely cleared in summer, nothing prevents you from sowing a green manure there so as not to leave the soil bare.

Leave a Comment