What Is Green Manure?Green manure, also called a cover crop, is a great way to add nutrients to the soil. Green manure means planting a crop that is meant to be incorporated into the soil to increase it's fertility. Green manures can be planted in the fall after the herbs have been harvested. You can also plant your green manures as part of your crop rotation during the growing season. If you plant your green manure to grown all fall and winter, it also doubles as a cover crop and helps keep the rich topsoil from being washed away.
You turn the green manure crop into the soil in the early spring. This is done when the soil is not warm enough to plant but is dry enough not not get compacted by working with it. If you have heavy soil, you will want to turn the green manure into the soil later in the fall so that it decomposes over the winter. It is better than working with wet, heavy soil. You should not walk on or try to work with wet soil if at all possible.
How Do I Plant Green Manure?To plant green manure properly, you will want to do so when it is going to rain. It is essential that the seed not dry out during the germination period. For a small herb garden, you can broadcast(or spread) the seeds by hand in an even manner. Mixing the seeds with sand or soil before spreading helps you have more control over where it goes. After you spread the seeds, rake the soil to cover them sufficiently for germination.
What Kinds Of Green Manure Are There?There are two types of green manures: Legumes and Nonlegumes.
Legumes are plants whose roots work with the bacteria in the soil to grab Nitrogen in the atmosphere. This is called Nitrogen fixating, and is helped along by an inoculant, or treatment medium to help the legumes work. Inoculant is available at garden centers in a powder form, and will greatly improve your yields if used. Some legume green manures are Alfalfa, clover and soybeans.
Nonlegumes are all other green manures like Ryegrass, Buckwheat and Oats. There is a form of Rye called Winter Rye, that will grow in the coldest of zones and be ready to turn under in early spring. No matter what zone you are gardening in, you will find numerous green manures to fit your needs. This is another reason that your county extension office is a treasure of information . Your county extension agent should be able to identify the best green manures for your area.
How Do I Choose What Green Manure To Plant?Choosing your green manure depends on when you want to seed and what type of soil you have. Some green manures require you to seed in the winter and others in the spring. It is best to combine more than one green manure and rotate what you plant from year to year.
Which ever you choose, green manure is a great way to add organic nutrients to your herb garden.