Like people in relationships, specific crops love and hate each other, based on the specific natures involved. Seedlings of transplanting size begin to interact more and more together with the plants near them. These associations come to be especially necessary as adult plants cultivate explicit  personalities, essences, and aromas. Green beans and strawberries, for instance, thrive better when they are grown in combination than when they are grown independently. To get really wonderful-tasting Bibb lettuce, one spinach plant should be grown for everyfour Bibb lettuce plants.

In contrast, no plants grow well in the vicinity of wormwood due to its noxious leaf and root excretions. On the other hand, wormwood tea repels black fleas, discourages slugs, helps to keep beetles plus weevils out of grain, and attacks aphids. Consequently wormwood is not a completely harmful herb. Hardly any plants are. Instead, they have their place in the fundamental order of things.

Weeds are often specialists and doctors in the plant community. They take extremely well to sick soil that needs to be built up and almost seem to seek it out. Where cultivated garden plants can't get by, weeds are able to withdraw phosphorus, potash, calcium, trace minerals and additional nutrients out of the soil and subsoil and concentrate them in their bodies. Plants seem to have strange instincts.

Weeds can be used to concentrate nutrients meant for future fertilization or to withdraw toxic elements, such as undesirable salts, from the growing area. A deficient soil is often enriched by adding weeds to man-made compost or else by returning their dead bodies to the soil as nature does.

Companion planting is the positive use of plant associations by gardeners, horticulturists, and farmers. A logical characterization of companion planting is: "The placing together of plants having complementary physical demands." A more appropriate description is the growing collectively of all those elements and beings that support life and growth.

Companion planting is nonetheless an experimental area in which much more research needs to be done. The age of the plants involved and the share  of each of the varieties of plants grown together can be significant, as can be their relative proximity to one another. Companion planting ought to, therefore, be used with some caution and much examination. You may want to study the causes of some of these advantageous relationships. Are they due to root excretions, plant aroma, or the pollen of composite flowers that attracts certain beneficial insects? Companion planting is a surprising discipline.