Maintain fertility of your soil with green fertilisers

To avoid worsening the condition of your soil in your garden between two crops you must cover this so as it is never bare. Soil which "does not work" will have to face phenomena such as exhaustion and erosion and risks being colonised by weeds.

Spreading fertiliser can allow this to be avoided. This method primarily consists of occupying the land at the end of the summer and the start of the spring by sewing certain varieties of plants. 

The advantages of green fertilisers for your garden 

The benefits offered by green fertiliser so as to be classified in two distinct categories. This will act on land, but also have positive surface effects.

Its advantages in land :

  • Green fertiliser from the vegetable families, such as vetch, clover or alfalfa fix the atmospheric nitrogen (N in the NPK of fertilisers) which is a vital element for your plants.
  • The roots of green fertilisers go deeper than those of other vegetables. They therefore bring more nutrients to the surface.
  • The foots furnish and break down the heavy and clay lined soil, 
  • After crushing and incorporation into the land, the green fertiliser will be transformed into assimilable mineral elements and humus, reducing the risks of attacks by parasites over the following crop.
  • It has the effect of increasing by fourfold   the population of earth worms which produce nutrients and furnish the land by digging tunnels.

Surface benefits :

  • Flowers are often beautiful
  • It draws many pollenising insects (bees and bumble bees) and small insects (ladybirds and larvae).
  • It does not require maintenance once sewn and its growth is rapid.
  • Its covering power avoids the proliferation of "weeds".
  • It protects the soil from erosion and drying out.
  • Once  rushed, dried and then incorporated into the soil this biomass will constitute an excellent organic vegetable fertiliser.
  • It covering power avoids the phenomenon of "slaking crust" which occurs after rain on clay and limestone soil.

What green fertiliser should I choose ?

You should respect the principle of crop rotation and choose a family of green fertilisers different to that from the previous and following crop.
The choice of green fertiliser is therefore essential. To assist you, here are some varieties of green fertilisers and their characteristics :

  • Mustard green fertiliser : Family of brassicas (e.g. cabbage, palm).
    It has yellow flowers. Its growth is very quick and it has solid covering capacity. It uses a lot of nitrogen and has roots which are relatively deep, it avoids risks of exhaustion by trapping nitrates.
  • Vetch green fertiliser : Family of fabaceae (e.g. beans, peas).
    Its flowers are violet blue. It fixes the atmosphere nitrogen thanks to bacteria which live in symbiosis with the vetch at root level forming nodosity. You can use this if your garden has clay land.
  • Sarrasin green fertiliser : Family of polygonaceae (e.g. : sorrel, rhubarb, ...). 
    Its flowers are white and very nectar rich. It is at home in poor and acidic soil, and has a good weed killing power.
  • Phacelia green fertiliser : Family of hydrophylaceae.
    Its flowers are very decorative and rich in pollen It is an excellent nectar rich plant which has a solid covering capacity. Its roots are highly developed and dig deep.

Solabiol Tip :
No vegetable belongs to the Phacelia family. You are, therefore, sure of respecting the crop rotation rules if you use it as a green fertiliser.


How and when should you sew green fertiliser ?

Using green fertiliser is simple as it requires little maintenance. We recommend the use of green fertiliser for vegetable gardens, but also for decorative gardens and annual masses between two seasons. It is advised to sew green fertiliser by the latest at the end of September-early October so as to have the time to develop before the first frost. Here is how to do so step by step :

  1. Harvest the last vegetables
  2. Do not wait for the land to dry out
  3. Roughly rake and sew the green fertiliser by burying the seed slightly
  4. Allow to grow without adding fertiliser
  5. Cut by using a cutter in a high position or a hedge trimmer at around 10 weeks prior to the date of planting your new crop
  6. Allow to dry for around 2 to 3 weeks after cutting
  7. Bury into the land and wait for 6 to 8 weeks
  8. Plant or sew your new crop