By: Amy-Lynn Albertson , Horticulture Extension Agent, Davidson County

            Many beneficial relationships can occur when different types of plants are grown next to each other.  This is known as companion planting. Companion planting allows the gardener to maximize use of sun, soil and moisture to grow mixed crops in one area. Some plants attract certain insects such as bees and butterflies are attracted to flowers such as butterfly weed, bee balm, sweet basil, savory and others.  There are also plants that repel certain insects. A diversity of plants is the easiest and most effective pesticide and fertilizer the garden has.  A pest can be discouraged from eating your favorite crop by planting crops it likes next to plants it cannot stand.   For example if you have a problem with squash bugs, on your zucchini plants you could grow catnip, nasturtiums, or spearmint next to it to help prevent pest problems.  Here is a list of plants and the insects they help repel from the Encyclopedia of Organic Gardening:

Aphids                                                 Nasturtium, Spearmint, Stinging Nettle

Bean Beetle, Mexican                           Potatoes

Cabbage Moth                                     mints, hyssop, rosemary, thyme, sage

Colorado potato beetle                         eggplant, greenbeans

Cucumber Beetle                                  tansy, radish

Cutworms                                            tansy

Flea beetles                                          mints, tomato interplanted with cole crops

Japanese Beetles                                  garlic, tansy, rue, geranium, datura

Leafhoppers                                         petunia, geranium

Slugs                                                    prostrate rosemary

Squash bug                                           tansy, nasturtiums, catnip, spearmint

Tomato hornworm                                borage, marigold

You can also use companion planting to improve soil nutrition.  Farmers have been doing this for years by rotating their crops.  One year they will grow corn, which is a heavy nitrogen feeder, and the next year they will grow soybean which puts nitrogen back into the soil.   You can do this in your garden by planting heavy feeders, and heavy givers together.  For example you could plant peas on a trellis with cucumbers underneath.  The cucumbers will use the nitrogen in the soil that the peas are giving back.  In addition, the peas would help provide shade, which cucumbers love.    Companion planting can also be used to aid light and heat requirements.  Lettuce lovers know that in the full sun and the heat of the summer, lettuce will quickly bolt and turn bitter.  By planting lettuce next taller, heat loving plants such as tomatoes, corn, and peppers you can provide shade for the lettuce, which in turn cools the growing area around the plant.  For more information on companion planting or other horticultural topics, contact Amy-Lynn Albertson at 336-242-2080.