Many old-time farmers and backyard gardeners have found the secret to growing produce successfully, year after year. But do you know how they do it?
We, on the other hand, may have a bumper crop for one or two years in a row and then run into problems that produce only stunted, unhappy plants.
Sound familiar? Take heart, this is a common problem that can easily be fixed once you understand why this happens.
Vegetable plants are very heavy feeders and consume high levels of nutrients during their short growing period. As a result, vegetable plants leave the soil tired and depleted of fertility.
A lack of soil fertility will result in slow growth and plants that can appear stunted.
Insufficient nutrients can also leave plants more vulnerable to pests and disease, because there are not enough reserves to fight off the attack. Just like us, when we haven’t been eating a balanced diet, plants can get sick due to a lack of vitamins and minerals.
In the same way that we regularly feed our bodies, we also need to regularly feed our plants. That’s where green manures come in.
What is green manure?
Plants are fed by drawing up nutrients through their vascular system from the roots. The roots draw nutrients present in the soil moisture and an effective natural method to feed the soil is with a green manure.
Green manure is a crop that is grown for the purpose of reinvigorating tired soil, adding nutrients and bulky organic material to the soil. Green manure is grown for a short time, usually only about six to eight weeks.
While the crop is still soft and sappy, it is slashed at ground level and dug back into the soil where it was grown. Because the growth is young, it is still fleshy, and full of nitrogen, which provides the next crop with the elements required for good strong leaf and shoot growth.
Green manure increases organic material and organic carbon in the soil, adding bulk and improving the structure of your soil. The breakdown of organic matter increases microbial activity and helps remediate any heavy metals present in the soil and reduces pathogens.
Veggies need a soil that has good tilth, meaning that the structure needs to be light and crumbly. A rich loam is ideal; it’s full of fertility and has good drainage capacity while still able to retain some moisture for roots to absorb.
What to use for a green manure crop
Any crop can be grown and dug back into the soil, but some plants are especially good for certain things.
A legume is grown for adding nitrogen to the soil and lucerne, peas, clover and lupins are used for this purpose.
A cereal or grain crop like wheat, buckwheat, oats or rye can be grown to add bulk organic material and provide a range of minerals. After it breaks down, the remaining humus helps improve the soil structure by opening up heavy clods in clay soil allowing better drainage and easier root development.
The two types of plants above can be sown together with a fumigant plant as well, such as mustard, fenugreek and marigolds, which are often used as green manures and dug into the soil to repel nematodes and other soil borne diseases. Microorganisms feeding on the extra organic material can work as good bacteria in breaking down pathogens.
When to grow a green manure
The best time grow your green manure is several weeks before you plan to plant your next season’s crops.
That means you can usually get 2 sorts of green manures – a warm season green manure for Summer and a cool season green manure for Winter or cooler months. A winter green manure crop will prepare the soil ready for spring veggie planting. Likewise, a summer green manure crop will prepare the soil ready for cool season veggie planting.
Choose a suitable variety of legume, cereal and fumigant for your area. If you want to know what is right to plant for your area, download my FREE planting guides here.
How to grow a green manure crop
After choosing the suitable varieties, broadcast the seed over the proposed garden bed. Rake the seed over the soil so it gets slightly covered by soil.
Firm the seed into the soil and water it gently. Keep the area moist until the seed has germinated. The garden bed should be sown heavily, more densely than you would normally grow plants together, since it will only grow for about 6 to 8 weeks.
Grow the plants until the crop reaches about knee height. Then, simply slash it all at ground level and dig it in to the soil. Leave it to rot down for a week and turn it all in again. The soil will be ready for planting your next crop after another week. Your soil will then be rich and full of life once again.
Now that you have your soil ready for planting, you’ll need to get started on growing your veggies. Want to know how to fast-track your way to a healthy lifestyle and get more home grown produce with personalised help from expert horticulturist, The Veggie Lady? Become a VIP Veggie Club Member and eat veggies from your own garden every day