Garden Mastery Tips
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August 1999 |
Companion Planting
When you try companion planting, you're using a centuries-old technique that gardeners have relied on for controlling pests and improving harvest. Now, modern gardeners are also beginning to appreciate the value and safety of using companion planting as a basis for garden pest control.
Today, gardeners who try companion planting are using methods based on historical and contemporary gardening folklore. While much of this folklore has not been substantiated, some scientists are working to test and document how different plants interact with each other and the world around them. Some of the most interesting research has centered on the different ways that plants can defend themselves against pests. Repelling pests is just one aspect of companion planting – attracting beneficial insects is another. Many plants attract nectar and pollen-eating insects, pollinate their flowers, and help set fruits and seeds. As a bonus, some of these nectar and pollen-eaters, like lacewings and hover flies – produce larvae that attack plant-eating insects.
What is companion planting? Companion planting is the technique of combining two plants for a particular purpose (usually pest control). The most dependable functions of companion plants are repelling smell, luring pests from crops, sheltering beneficial insects, and combining complementary crops. The aroma of garlic and onions is a powerful deterrent to many pests. Besides producing pretty (and edible) flowers, nasturtiums may lure aphids from your crops. Flat, daisy-like flowers are a good source of pollen and nectar for a variety of beneficial insects. Sage, spinach, and borage are some of the companions that grow well with tomatoes.
How does companion planting work? When you arrange your garden according to the principles of companion planting, you combine plants that can share resources – water, light, and nutrients – and take advantage of the natural defenses plants use to protect themselves from pests, diseases, and other plants. Increasing the diversity of your garden plantings and incorporating plants with particularly useful characteristics are both part of successful companion planting.
Just as some plants grow especially well together, a few are able to keep other kinds of plants from crowding in around them. These are allelopathic plants. These plants work by releasing inhibitory chemicals into the soil or air – a neat trick for making sure nothing is going to compete with a plant for its share of rooting space, moisture, and nutrients.
The amount of satisfaction and success you get from companion planting depends on how much effort you put into it. Even some of the most basic principles, like increasing diversity and rotating crops, can bring excellent results. But to get the most benefits, you need to be willing to do some planning and experimenting. Enjoy your successes, learn from your failures, and keep an open mind – these are the keys to successful companion planting.
For a complete "Plant by Plant Guide" refer to Rodale's Successful Organic Gardening Companion Planting
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