The term “green manure” generally refers to plants grown for the sole purpose of being incorporated into the soil to enrich it with organic matter or to smooth the soil. The best time to sow ground cover crops for green manure is after harvesting vegetables and herbs. What are the advantages of green manure in autumn?
Plants used for green manure grow quickly and are used to cover infertile soil. Their leaves are good for suppressing weeds, and their roots help keep soil from washing away in the vegetable garden. When planted while they are still young, they add nutrients back to the soil and strengthen the soil underfoot.
Planting green manure plants after harvesting a garden's crops and incorporating them into the soil immediately before the next planting season is an excellent way to enrich the soil with beneficial, organic matter. Commercial farmers who want to increase their yields typically plant green manure crops, but amateur gardeners can also benefit from this strategy.
Green manure – advantages of the natural method
Green manure has many advantages!
Increasing soil fertility
Green manures can reach nutrients deeper in the soil than the roots of most crops. Clover and vetch, both members of the legume family, share this ability by absorbing atmospheric nitrogen via root nodules. Once the plant reaches maturity, it can be returned to the ground where it will dissolve and replenish the soil's nutrient balance. The millions of tiny microcosms in the soil are also nourished by this process and encouraged to produce a fertile growing medium.
Improving the structure of the soil to make it more water efficient
Soil structure can be improved through the use of green manure, regardless of whether the soil is thick and loamy or light and sandy. The broad, often deep root system of green manure plants loosens compacted soil and improves drainage. These roots are like sponges, sticking tightly to soil particles in light soils. They prevent water from washing out the soil and nutrients from being lost.
Destruction of weeds
Mother Nature takes advantage of bare ground. Uncultivated land quickly becomes overgrown with weeds. Covering the soil with fast-growing green manure plants such as mustard can smother weed seedlings and eliminates the need for hoeing. Plants like clover are good in the long run. In the early days after sowing, the weeds compete with the clover. When you cut back the weeds,the clover growsbigger and stronger than the weeds, and you'll have more usable nitrogen in the soil when you dig it up.
Attracting predatory insects and other beneficial pests
Beneficial insects that eat pests such as aphids can be attracted to the garden by planting a small bed of red clover or phacelia. The cool, moist soil beneath a green manure plant is also ideal for slug hunters such as frogs and beetles.
Which plants for green manure?
Green manure can be made from a variety of plant groups and individual species.
Pay attention to crop rotation
The likelihood of insect infestation can be reduced by rotating crops when growing green manure crops. If a crop is taken out of production for a long period of time, the specialized pests that feed on it starve. The green manure should therefore not consist of plants of the same family as the previous orsubsequent vegetables. For this reason, sowing yellow mustard, oil radish or winter rape as green manure on harvested cabbage beds is not recommended. These plants, like all other brassicas, contribute to soil depletion and the spread of clubroot, as they belong to the cruciferous family.
Tipp:You should not sow lupins, clovers, vetches and other butterflies for green manure before or after peas and beans.
To avoid soil fatigue, it's best to choose three different plant species (from different families!) for your green manure, even if you want to sow them all at once. Another option for sowing green manure plants once is the commercially available green manure mixtures. In this way, the unique properties of many plant species can be combined.
Green manure in autumn – freezing and winter-hardy plants
It is important to know in the fall whether the green manure plants you have chosen are sensitive to frost. You can save time in the spring by simply mulching the plants instead of digging up the green manure. However, the plants cannot develop in this way in winter. Therefore, it is best to grow both hardy and freeze-hardy species.
Freezing plants
- Sommerwicke (Vicia sativa)
- Real buckwheat (Fagopyrum esculentum)
- common flax (The most common linen)
- Rauhafer (Oatmeal witch hazel)
- Perserklee (Clover resupinatum)
- Phacelia (Phacelia tanacetifolia)
- Gelbsenf (White mustard)
Hardy plants
- Rotklee (Trifolium pratense)
- Incarnate-Klee (Incarnate clover)
- French ryegrass (Lolly talking)
- Winterwicke (A villous vice)
- Yellow lupine (Lupinus)
Application of green manure
- Sow the seeds in rows or scatter them over the ground and work them in with a rake.
- Cut the plants and allow them to wither if the site is needed for planting.
- Plants and leaves should not be buried deeper than 25 cm.
- Decomposing green matter can stunt plant development, so it is best to wait at least two weeks after burying before sowing or planting.
Green manure in the vegetable garden
After harvesting crops such as potatoes, apply green manure wherever the ground is still bare. Phacelia and yellow mustard are two fast-growing plants that can be incorporated into the soil just 6 weeks after sowing.
Planting winter rye or winter vetch in the fall will protect the soil from erosion during the cold months. Once the soil warms up, you can grow your hungry summer vegetables like zucchini and runner beans in it.
If you're growing tall plants like sweet corn, cover the soil between rows with a low-growing green manure like clover. This way, fewer weeds grow.
You can grow green manure plants in a plot of your new allotment in the first year if the soil has been stressed too much in the past. This way you can nourish the soil and get it in shape for next year, while also reducing the area you have to cultivate in the first year.
Plant green manure and watch the flowers bloom! Red clover and phacelia are two particularly magnificent flowering plants. Flowers with lots of nectar attract bees. Fill empty spacesin your floraland vegetable garden by sowing seeds here and there in the fall.
Feed the orchard
Near nitrogen-hungry currant bushes, vetch planted in the fall can fix the element in its root nodules for use later in the growing season. Cut the plant back in spring and allow the dead leaves to rot on the ground.
Clover is a good example of a long-term green manure that can be planted at the base of fruit trees. This will help you keep weeds at bay and create a comfortable environment for animals that hunt pests.
When should you start burying?
Three to four weeks before you plan to use the land again, or when the plants are close to maturity, whichever comes first, you should dig in the fertilizers. The new vegetation will quickly decompose and enrich the soil. Avoid allowing the plants to become heavily woody or produce seeds. Mustard, for example, should be buried as soon as possible after the first flower buds appear, as the plant quickly goes to seed once the flowering period begins.
Simply use a sharp spade to get the plants back into the ground. Make sure you break up any really hard lumps as you do this. When mustard and buckwheat are young, you can simply chop them off and leave the leaves in place or add them to the compost heap.
An alternative to burying, as already mentioned, is to leave the sensitive plants to the frost and leave the frozen leaves in place to protect the soil.
