By Betty Hensley
UCCE Master Gardener of Tuolumne County
Just as there are many wonderful benefits to finding that right companion in life, there is also something special and fascinating about companion planting.
According to the Cornell University Gardening Resources Ecogardening factsheet No. 10, Companion Planting:
“Plants are very active in ways that are not so obvious to the casual observer. For example, plants change the chemistry of the soil, and influence the types of microorganisms that grow there. They actively compete with other plants for space. Some will poison their neighbor’s offspring to maintain a competitive advantage, while others change the environment in ways that benefit other species. Plants wage a constant battle with insects, relying heavily on chemical warfare.”
Plants that assist each other to grow well, plants that repel insects — even plants that repel other plants — are all part of the gardening world that has never been fully explored. Again, following Cornell University’s advice, try some of the following combinations that folklore says are effective. Observe the effects carefully and document your observations. Create your own experiments and share your results. “Testimonials that are shared by many observers often turn out to be valid.”
Vegetable gardeners may find that companion planting provides many benefits, one of which is protection from pests. For instance, a major enemy of the carrot is the carrot fly, whereas the leek suffers from the onion fly and leek moth. Yet when leek and carrots live together as companions, the strong and strangely different smell of the partner plants repel the insects so much that they do not even attempt to lay their eggs on the neighboring plants. Even when plants are affected by diseases, a mixed plant culture can usually reduce the problem.
Wild plants also play a vital part in the plant community. Some have the ability to collect trace minerals from the soil. They actually can store in their tissues up to several hundred times the amount contained in an equal amount of soil. These plants, many of which are considered weeds, are useful as compost, green manure, or mulch.
An entirely different type of community life is that of a fruit and nut trees. For many of this group, the choice of good companions is not only helpful but essential. Have you ever experienced the disappointment of having a beautiful fruit tree blossom, be visited by the bees, and yet fail to bear? There is a reason of course, and it lies in pollination-companion planting.
Here is a brief list of some of the many possible combinations of companion plants that you may want to try:
• Dill and nasturtiums both make good companions for squash and cucumber because they repel squash bugs and attract beneficial insects
• Sweet corn does well with potatoes, peas, pumpkins and squash (corn, legumes and the squash family are the traditional “Three Sisters”)
• Sow two or three radish seeds in cucumber hills to protect against cucumber beetles. Do not pull the radishes, but let them grow as long as they will
• Lettuce grows well with strawberries, cucumbers and carrots
• Pumpkins grow well with corn, but pumpkins and potatoes have an inhibiting effect on each other
• Because of its saponin content, spinach is a useful pre-crop and does well planted with strawberries
Tomatoes dislike cabbage, potatoes and fennel, but will protect asparagus
And last but not least, is garlic. Garlic is often recommended as an effective control for many insects because its smell repels insects and can mask scents that attract insects. Interplant garlic among your vegetables.
Master Gardeners are available to answer home gardening questions at local farmers markets, and Tuesday through Friday, 9 a.m. to noon, by calling (530) 621-5512. Walk-ins are welcome at our office, located at 311 Fair Lane in Placerville. For more information about our public education classes and activities, go to our Master Gardener website at www.ucanr.edu/sites/EDC_Master_Gardeners/. Sign up to receive our online notices and e-newsletter at www.ucanr.edu/mgenews/. You can also find us on Facebook.
Note: Betty Hensley is a long-time Tuolumne County Master Gardener who grows an abundant vegetable garden, and graciously agreed to share her article with Village Life readers.