Companion planting is a phrase that has taken on many meanings for today’s gardeners. Within the scientific community, companion planting is also called intercropping and is a form of polyculture, which describes a method of planting species of plants together for mutual benefit, usually in agricultural situations.
For the layman, companion planting is best described as the practice of planting two or more plants together to enhance the growth and quality of nearby plants; to provide maximum ground cover; and, when possible, to improve the soil. This approach to gardening offers many benefits, with the trade-off being that more thought needs to go into the garden planning stage when deciding which plants should go where. Although there is no scientific explanation as to how or why the plants benefit one another, when planted in “companionable ways,†much has been learned over the years — with a great deal of success.
Some of the successful companion planting relationships are due to the release of chemical secretions at the roots, which may affect other plants or have an effect on organisms in the soil. It has been theorized that companion planting benefits may result from the plant releasing certain gases or odors that can repel pests from either the roots or the above-ground parts of the plant. With certain predators (notably insects that damage the plants) out of the way, the plants can flourish. The same goes for other potential pairings. One plant may have the ability to do something like provide structure, add nitrogen to the soil, or offer shade in such a way that makes another plant flourish without hurting itself.
There have been lab studies where scientists have tried to replicate the results of companion planting — with mixed results. By adding the juices of pairs of plants to a 5 percent copper chloride solution and allowing it to crystallize slowly on a glass plate, Dr. Ehrenfried E. Pfeiffer and Dr. Erica Sabarth of the Bio-Dynamic Association were able to predict which plants would be companions and which would be antagonistic from the resulting crystallization patterns. Their findings, along with the trial and error of numerous gardeners, were summarized in a pamphlet by Richard Gregg in 1943 called Companion Plants and How to Use Them. Today, similar studies use paper chromatography techniques for related tests.
The companion fruit suggestions in this book should be used as a basis for your own experimentation, not as a proven guide to success. One of the most important considerations when you look at choosing your own companion fruits is to not lock yourself in by this book’s information. Try some of the combinations out for yourself, experiment with new ones, but also play around with the spacing between the plants and the ratio of one plant to another.
As you become more familiar with the subject, you will eventually realize there is conflicting information — partly due to everyone’s individual experiences based on geographical location, climate, and garden conditions. Therefore, the rule to companion gardening is simple: Try it out for yourself. Keep a record of your attempts and have fun with it. Plant basil in among your tomatoes and watch them grow like mad. Try basil in with the peppers for a similar result. Or, try adding in parsley as it can help tomatoes grow strong and healthy.
Companion planting requires a gardener to shake off his or her idea of traditional gardening and make room for new concepts. You will need to let go of concepts that define what a weed is and consider the fact that the weed could have value. Are there stinging nettles, a common weed across the United States, in your area? Have you spent hours trying to eradicate this weed that can grow up to 10 feet tall? Well, stop because they have value. If you grow them close to aromatic herbs, they are supposed to increase the aromatic oils in these herbs by as much as 75 percent. Stinging nettles, like foxglove and lily of the valley, are reported to improve the length of time the fruit from their companion plants can be kept once picked, particularly tomatoes.
