Last month we shared an article with you about companion planting with a focus on why certain plants “don’t play well together”. As promised, this month we’re going to focus on the same topic but from the perspective of plants that are “good citizens” and make good neighbors. What makes a good companion plant you ask? Well, in general, a good companion plant provides some benefit or support to the other plants around them and many of us learned about good companion plants when we were still in elementary school.
Perhaps the best example of companion planting is one we usually learn about in our first U.S. history class. Native Americans taught the pilgrims about companion planting. Corn, beans, squash and pumpkins were planted together and this was done on purpose. Corn plants provided a support system for the beans to climb on while the beans, which are legumes, conserved nitrogen in the soil which the corn required. At the same time, squash and pumpkins, which grow rapidly, have large leaves that act as a natural weed block as well as an effective mulch to keep moisture in the soil. Of course, at the time the Native Americans knew nothing about nitrogen but they certainly knew that these plants worked together in harmony.
Have you ever wondered why many gardeners mix flowers and vegetables together? It is less about the aesthetics and much more about the benefits those flowers bring to the vegetables. For example, many French vegetable gardens also have beautiful dahlias that grow side by side with tomatoes, beans and other vegetables. The reason this is done is because dahlias are very attractive to bees and butterflies which pollinate the vegetables. Without these pollinators there would be no fruit or vegetables on our tables!
Another well-known example of companion planting is mixing marigolds with tomatoes. Marigolds repel soil borne pests known as nematodes whose favorite meal seems to be the roots of the tomato plant. While they look pretty those marigolds are providing a valuable service to their tomato neighbors. While there is no scientific evidence that supports their argument, our gardening friends in France insist that Foxglove, which is a biennial, be planted in their gardens as it appears to stimulate growth as well as enhance the disease resistance of the plants around it. Sometimes the reverse is true and the vegetable can be the plant providing the benefit to the flowers. Tomatoes are often grown in proximity to Roses as tomatoes have properties that help ward off black spot fungus which many Rose varieties are highly susceptible too.
Not only do flowers provide benefits in a vegetable garden but so do many herbs which have aromas that either repel inspects or seem to provide camouflage protection to their neighbors. For example, purple sage can be grown to ward off insects that would feast on purple cabbage and oregano, also known as marjoram is a good friend to tomatoes and cucumbers as it repels tomato hornworms and cucumber beetles. As a matter of fact based on our research oregano appears to be a good neighbor to just about every plant in the garden!
Companion planting is not an exact science but there definitely appears to be enough historical evidence to support this concept. If you would like to learn more about which plants may work well together try downloading this companion planting guide (http://downloads.smilinggardener.com/files/images/articles/vegetables/companion-planting-chart.pdf) or contact us through the Ask Us section of our website or on our Facebook page.