While designing and planting your garden or landscape, a few nitrogen-fixing plants are a good thing. If you’re planting for a heavy nitrogen feeding plant like corn you may need a little extra planning to make the most of it. There are three rules for using nitrogen-fixing plants to improve your garden no matter what method you use:
Basic Rules For Using Nitrogen Fixers
- Make sure the crops are close enough to your nitrogen-fixers that there is some chance of the roots growing in the same root zone.
- Cut the nitrogen-fixer back during bloom time to keep the nitrogen from being put into the seed as it develops.
- Use the cuttings to enrich other areas of your garden.
Partnering Nitrogen Fixers With Annuals, Perennials, and VegetablesNext, you need to decide which plants you want supported by nitrogen. If they are annual, you can plant them in between rows of perennial or annual nitrogen fixers, or you can mix them in somewhat randomly. You do need to keep in mind that you need to allow enough space for both the primary crop and the secondary crop to have the light and airflow they need to thrive. In your vegetable garden this planting can be as simple as planting one row of beans or peas, then planting two rows of lettuce, then one of peas or beans again. If you are looking at mixing the crops, the traditional Native American three sisters planting of corn, beans, and squash in the same mound is the perfect combination of productive crops that are supported by a nitrogen fixing plant. If your crop is perennial, then it is easiest to plant perennial nitrogen fixers so you have less risk of damaging your primary crop’s roots by repeated plantings and removals of the nitrogen fixer.
Crop RotationsWith both perennials and annuals, old-fashioned crop rotation includes a year or more of legume growing to provide a nitrogen boost so that old soils don’t wear out. This has been one of the two main ways of getting nitrogen for farms and gardens for centuries. Typically a nitrogen fixer is planted, followed by a high nitrogen needing crop for one year which is then followed by a lower nitrogen demanding crops for a year or two. Then the cycle is repeated. After decades, other soil nutrients can be depleted but the nitrogen will continue to be renewed.
A Cheap, Intelligent Way to Provide NitrogenThis is just a summary of what can be done, but to put it into real action takes a bit more understanding, planning, and work. Throughout history, using plants has been the most reliable and trustworthy method to build soil nitrogen. And really when you look at the energy costs that go into producing synthetic nitrogen fertilizer, as well as the problems with synthetic nitrogen running off into our water and leeching into our soil, nitrogen fixing plants are also the most intelligent way to make sure that the rest of our plants are healthy and strong.
If you are new to this, I suggest you take a small part of your growing area and experiment with providing nitrogen from plants only. I predict that you will be pleasantly surprised.