Green manure, what is it?
When we talk about green manure, we are talking about fast growing plants. We can cite, for example: crimson clover, rye, phacelia, alfalfa, mustard, etc. These plants are to be sown on bare soil which they will cover entirely as they grow. This temporary culture must then be cut and left on the ground or buried for enrich the earth. Depending on the needs, it can be left for a few months or a full season.
The advantages of green manures
Green manures offer many advantages.
- They limit the development of herbs considered undesirable by allowing the ground not to remain bare.
- Their presence allows naturally decompress the soil.
- This organic matter will encourage microbial life.
- We thus benefit from a more aerated floor and therefore, better drained.
- Through the degradation of green manure, the soil is nourished.
- Some of the green manures offer a beautiful flowering and help attract pollinators.
Choosing the right green manure
You can choose to sow a specific green manure or a mixture. Here are the criteria to take into account:
- To choose it well, you must be interested in soil condition and determine the goal you want to achieve. Thereby :
- if the ground is too compact, prefer species with plunging or pivoting roots. You can bet on phacelia, rye, flax;
- for weed control, choose a green manure that covers efficiently and grows quickly;
- in the case of a rather poor soil, opt for legumes.
- You can also opt for this or that green manure depending on what you want to grow after. For example, in anticipation of growing carrots, it is better to choose a fertilizer that will loosen the soil. Conversely, it should be avoided to put mustard or another crucifer before growing cabbages, because they are from the same family.
- The time lapse between cultures is also an important criterion. If, for example, this period of time is relatively short, you should not choose a green manure with a long growing cycle.
- Finally, time of year will also determine the type of green manure you can use.
In summary, to choose your green manure, determine the growth you want (slow, fast or medium). You will then be interested in the root system and the characteristics you want. Finally, you can choose according to the sowing period.
When to sow green manure?
Green manures must be sown before or after cultivation of the plot. Since there are different plants that can be used as green manure, it is possible to sow it throughout the year. For example, if we take the case of phacelia, undoubtedly the most decorative and the most melliferous green manure, you can sow it in July, August or spring. In general, it is advisable to sow green manures at the end of the season, when the ground is free. Thus, the ground does not remain bare.
Sow green manure
To sow your green manure, you can proceed as follows:
- Start with prepare the earth. If necessary, loosen the soil first, then level it. It may be helpful to break up clods of earth.
- You can then broadcast green manure respecting the dosages for each species.
- After sowing, tamp with a lawn roller, in the case of a large area, or with the back of a rake. Depending on the species, it may be necessary to bury it.
- Then proceed to a watering.
Mowing, to fully benefit from green manure
Once your green manure has grown, it is necessary to mowing before the flowers go to seed. This way you will avoid spontaneous seedlings. This means that you have to mow at the start of flowering. At this moment, organic mass is at its maximum.
Two scenarios:
- For a cultivation immediately after green manure, you have two options: mow it or pull it out. You must then collect it for use in the composter or use it as a mulch for a plot that is not going to be used immediately.
- If the plot is not immediately used, you can simply mow green manure and leave it there. You will then have to wait between 15 days to 3 weeks before being able to set up the desired culture.