How to Start Your First Organic Garden (Part 2)
Although atmospheric nitrogen (N2) makes up nearly 80% of our air, plants cannot use nitrogen in the N2 form. N2 is considered an inert gas because it is very stable-it is composed of two nitrogen molecules that are held together by a triple bond. Plants need ammonia, which is nitrogen combined with hydrogen (NH3), in order to manufacture amino acids, proteins, and other essentials. However, they are unable to break the N2 bond without help.
Nitrogen Fixation
Legumes and rye are well known for their ability to 'fix' nitrogen. Actually, they both have a symbiotic relationship with various strains of Rhizobium bacteria. Rhizobium bacteria attaches itself to the roots of host plants and absorbs both nitrogen and hydrogen (NH2) from air in the soil and uses some of the plant's energy (carbohydrates) to change it to ammonia (NH3). The plant absorbs the NH3 and converts it to NH4 (ammonium nitrate). Ammonium nitrate is a fertilizer for the plant. Both the bacteria and plant benefit from the trade-off.
If you plant oxygen-fixing legumes, such as beans or peas, near nitrogen loving members of the cabbage family, such as broccoli and kale, the cabbage family and legume family will both smile.
Repelling pests and Attracting Help
Some plants emit chemicals from their roots or leaves, called allelochemicals, which repel pests. As an example, tomatoes repel caterpillars from diamondback moths, which like to use cabbage leaves for food.
Other plants attract insects that prey on pests that would otherwise damage nearby plants. As an example, beans attract insects that eat corn pests, such as leaf beetles.
Space and Other Factors
Plants that need partial shade often grow best in the shade of a larger plant or bush. As an example, spider flowers (cleome) can provide the partial shade that lettuce prefers. Sometimes a row of sturdy plants can protect weaker plants from wind damage.
Root depths vary from one plant to another. You can take advantage of this difference to grow more vegetables in a given area. As an example, by planting shallow-rooted onions in close proximity to deep-rooted carrots, you can grow more of each in your vegetable garden.
The Unexplained
When basil is planted in close proximity to tomatoes, both grow very well. This is a beneficial relationship that hasn't been explained.
Another similar relationship is between climbing beans, corn, and squash. When the three grow together, they are all happy, but know one knows exactly why.
Nitrogen Fixation
Legumes and rye are well known for their ability to 'fix' nitrogen. Actually, they both have a symbiotic relationship with various strains of Rhizobium bacteria. Rhizobium bacteria attaches itself to the roots of host plants and absorbs both nitrogen and hydrogen (NH2) from air in the soil and uses some of the plant's energy (carbohydrates) to change it to ammonia (NH3). The plant absorbs the NH3 and converts it to NH4 (ammonium nitrate). Ammonium nitrate is a fertilizer for the plant. Both the bacteria and plant benefit from the trade-off.
If you plant oxygen-fixing legumes, such as beans or peas, near nitrogen loving members of the cabbage family, such as broccoli and kale, the cabbage family and legume family will both smile.
Repelling pests and Attracting Help
Some plants emit chemicals from their roots or leaves, called allelochemicals, which repel pests. As an example, tomatoes repel caterpillars from diamondback moths, which like to use cabbage leaves for food.
Other plants attract insects that prey on pests that would otherwise damage nearby plants. As an example, beans attract insects that eat corn pests, such as leaf beetles.
Space and Other Factors
Plants that need partial shade often grow best in the shade of a larger plant or bush. As an example, spider flowers (cleome) can provide the partial shade that lettuce prefers. Sometimes a row of sturdy plants can protect weaker plants from wind damage.
Root depths vary from one plant to another. You can take advantage of this difference to grow more vegetables in a given area. As an example, by planting shallow-rooted onions in close proximity to deep-rooted carrots, you can grow more of each in your vegetable garden.
The Unexplained
When basil is planted in close proximity to tomatoes, both grow very well. This is a beneficial relationship that hasn't been explained.
Another similar relationship is between climbing beans, corn, and squash. When the three grow together, they are all happy, but know one knows exactly why.
