In nature, where plants grow without cultivation, there is always a mixture of plant types growing in any given area. The variety of plants living in these areas depends upon the soil type, local climatic conditions and horticultural history. With a few exceptions, the plants that grow together in the wild are mutually beneficial, in that they allow for maximum utilization of light, water and soil to the benefit of each other.
Companion plants and the home garden
Plants needing less light live in the shade of those which must have full light, while the roots of some plants live close to the surface, and others send their roots far down into the subsoil. Some plants will hurry into bloom and flower early in the year before their neighbors have yet to produce leaves, which will cut off the light supply later in the year.
The home gardener can accomplish this same effect in the garden. This is known as companion planting and it is a key element in organic gardening. Companion planting enables you to maximize the natural benefits of sun, soil and moisture in your garden. By growing selectively diverse crops in your garden you can aid nature in supplying the conditions for robust growth and insect protection.
In planting an organic garden, you should use plants that are mutually compatible and make demands on the environment at different times and in different ways. Vegetables may be divided into heavy feeders, light feeders, soil-conserving and soil-improving crops.
Heavy feedersThe heavy feeders should be planted in soil that has been newly fertilized. Among the heavy-feeding vegetables are cabbage, cauliflower, all leaf vegetables as chard, lettuce, endive, spinach, and celery, celeriac, leeks, cucumbers, squash, corn, and tomatoes. The heavy-feeding vegetables should be followed by such light feeders as pole beans, bush beans and other legumes.
Light feedersLight-feeding vegetables are great lovers of composting. Also, better than other kinds of plants, they seem to use the finely pulverized raw rocks and make phosphorus, potassium and many trace elements available to other plants.
Light feeders are vegetables such as carrots, beets, radishes, turnips, and rutabagas. Most herbs are also light feeders.
Beneficial Companion PlantsSome plants have a beneficial effect in the garden by virtue of some peculiar character of their growth, their scent or their root formation and soil demands.
Plants with peculiar benefitsAmong these plants are sunflower, hemp, blossoming hyssop, thyme, savory, borage, and other good bee-pasture plants. Odoriferous plants, including those with aromatic oils, play an important part in determining just which insects visit the garden. Hemp, for instance, is said to repel the cabbage butterfly.
Insect repellent properties of plantsHowever, there is more to companion planting than just arranging the physical needs of plants for optimum use of your garden space. Although the hard scientific evidence is often lacking, there is a whole host of organic insect control properties and biological insect controls attributed to different combinations of plants. In addition, there are combinations of plants that seem to be natural enemies.
When planted too close together, the result is often depressed yields of one or both plants. In most cases, plant scientists still do not know all the why's of these relationships. Many theorize that it is root exudates, or leaf secretions. The odor of one plant may be desirable to an insect, but the odor of a neighboring plant may overpower the attractive scent and send the insect packing.
Diversify your garden plantingWhat is reported as working in one garden may not work in yours. Then too, you may hit on a beneficial pairing not yet reported.