We gardeners spend so much time worrying about what our plants need that we often forget that they have grown well for millennia without us. Suppose we take a step back from our self-aggrandizing human nature and instead draw our inspiration from real nature?
It would save time, money and protect the environment by reducing the need for fertilizers, pesticides, herbicides and even garden stakes.
Many plants co-exist in symbiotic or non-complementary relationships. Native Americans noticed this centuries ago and used their findings to take advantage of the natural inclinations of plants.
Their “Three Sisters” method of growing corn, beans, and squash together is perhaps the best-known example of “companion planting,” a practice that puts plants to work to maintain good health, as well as their neighbours.
The trio serves well: as the squash spreads its large, spiny leaves over the ground, it provides shade to keep roots cool, suppresses weeds, and discourages animal browsing. Corn grows upright to support climbing beans, which repay the debt by fixing nitrogen in the soil to fertilize all three plants.
Like these beans, all legumes, such as peas, lentils, soybeans, and peanuts, take nitrogen from the air and convert it into a form that nourishes the soil — and the plants growing in it. At the end of the season, alfalfa or clover can be planted in cleaned vegetable beds and turned over the following spring to add valuable nutrients to the soil. These nutrients reduce or even eliminate the need for fertilizer during the growing season.
Some plants ward off insects or ward off disease. Basil, for example, repels dust mites, aphids and mosquitoes and has antifungal properties. It also repels tomato worms, proving it works just as well in your garden as it does in your Caprese salad.
Tomatoes pay for it by protecting asparagus from beetles and roses from black spot, an often fatal fungal disease. But keep tomatoes away from potatoes, cabbage and fennel, which will stunt their growth. Nasturtiums, on the other hand, enhance the flavor of their tomato and squash neighbors.
French and African marigolds exude a chemical that repels many insects and outright kills nematodes, parasitic eel worms that damage the roots of vegetable and fruit crops.
Chrysanthemums produce pyrethrins, natural chemicals that repel ticks, fleas, mosquitoes, flies and other insects so well that they have been imitated to create synthetic pyrethroids, which are sold as herbicides and insect repellents. Why treat your plants with lab-made chemicals when their inspiration is naturally available – and carries no warning label?
Do you have slugs? Plant lavender. Similarly, chives chase away aphids from lettuce and roses, and sage repels cabbage moths. Oregano and radishes protect against squash beetles and cucumber beetles, but sunflowers inhibit the growth of beans and potatoes.
Zinnias and parsnips attract ladybugs, which are gluttons for aphids and cabbage maggots. So do parsley and dill, but choose one or the other because they don’t get along.
Onions and garlic will retard your asparagus, beans, leeks and parsley, but deter insects and disease from beets, cabbage, carrots, lettuce, sage, strawberries and tomatoes.
Cabbage and cauliflower, although related, are like conflicting cousins that need to be seated separately or they will spoil the fun of your family entertaining.
Plant friends with friends, and everyone will get along. Your garden – and your wallet – will thank you.
Jessica Damiano writes regularly about gardening for The Associated Press. A master gardener and educator, she writes The Weekly Dirt newsletter and creates an annual wall calendar of daily gardening tips. Send her a note at [email protected] and find her at jessicadamiano.com and on Instagram @JesDamiano.