Companion Planting in the Garden

Companion planting, also known as interplanting crops, has been used for centuries by farmers all over the world. Interplanting is fundamental in Asian cultures. The ancient Romans knew that orchards were healthier if they planted grains alongside their fruit and nut trees.

Native Americans routinely planted corn with squash and beans, passing along this practice to early settlers. The settlers learned to train grapes to grow between asparagus, whose beds also contained carrots.

Grow Crops Organically Without Using Chemicals

In her book Good Neighbors: Companion Planting for Gardeners, Anna Carr explains in detail the history, practices and benefits of interplanting in the garden to grow crops organically without the use of commercial chemicals.

She explains how a ‚”monocropped field is an unnatural, unstable ecosystem, which requires chemical pesticides, herbicides and fertilizers for its existence.” Interplanting helps maintain balance naturally, as a garden created in this way mimics nature.

One of the best-known examples of companion planting is growing marigolds with tomatoes, potatoes and roses. The marigolds act as a natural pest repellent, and some varieties suppress the growth of weeds.

Ways to Interplant to Create a Healthy Garden

Carr discusses how ‚”a diversity of plants provide shelter and food for insect predators and parasites that help control potential pests” and how they create “a stable environment where no population is likely to get out of hand.”

She suggests several ways to use companion planting methods to get the best results:

• Mix light-loving plants with those that prefer shade. The shade lovers will thrive below the taller, sun-loving crops, but be mindful that the tall plants do not overgrow and cut off too much light.
• Pick plants that grow to different depths. To encourage efficient use and dispersal of soil nutrients and water, place deep-rooted plants near shallow-rooted ones. An example is growing pumpkins with celery or onions.
• Understand how planting legumes restores soil. Legumes like soybeans, alfalfa and clovers are traditionally part of crop rotation plans because they enrich the soil with nitrogen as they decay, helping to maintain nutrient balance.
• Plan out the design of the garden. Maximize space by interplanting a second crop either between or within the rows of a single crop. Consider the shape of the beds, whether square, round, or as a border.
• Create a habitat for beneficial insects like bees and ladybugs. Surround the garden area with flowering plants like daisies, asters or perhaps a fruit tree to attract pollinators and helpful predators.
• Consider growing a tall crop or hedge around the garden. It will serve as a windbreak and trap aphids and other wind-borne insects in the hedge rather than the garden.
• Beware of Toxic Plants. Some species will kill crops that are planted nearby. This is called allelopathy. For instance, the black walnut tree is known to be toxic to tomatoes, potatoes, peppers, blueberries, and more.

Achieve Efficient Results With Companion Planting

Perhaps the greatest benefit of companion planting is that, by thoughtfully timing the planting of crops, the whole garden can be used efficiently throughout the growing year. This is called relay planting.

By sowing a new crop in between another that is nearly finished, the new seedlings will benefit from the shade and moisture provided by the crop that is dying down, and not a minute of time or inch of space has been wasted. An example of a three-way relay planting is to grow early peas, followed by broccoli, then summer squash.

The gardener should consult an index of companion plants when planning the crops that are to be grown. Companion planting results may vary depending on climate and location. And while some evidence suggests that the practice might not solve, but rather encourage pest problems, the gardener or farmer who experiments with combinations that have been shown through history to be effective may achieve the most desirable results.

Sources:

Carr, Anna. Good Neighbors: Companion Planting for Gardeners. Emmaus: Rodale Press, 1985.