Herbal Besties ↠ Companion Planting

Companion planting!

Herbs and vegetables woven together, spinning a lovely web of symbiosis.

A staple in many cultures and traditions around the world, and for good reason, it works!

What is companion planting? Companion planting is defined as “the planting of different crops in close proximity for any of a number of different reasons, including pest control, pollination, providing habitat for beneficial insects, maximizing use of space, and to otherwise increase crop productivity. *”

This technique can be found all over the world in many traditional organic and biodynamic farming practices. The famous Three Sisters Garden is a technique found in many Indigenous American cultures which includes squash, beans, and corn grown together for their synergistic benefit. In China, mosquito ferns have been grown with rice for at least 1000 years.

Chemical pesticides — the modern solution to the age-old problem of pests and weeds —could be one of the largest hazards we currently face to our health, and to the health of our environment. Some unintended consequences from non-discriminate chemical pesticide use include: environmental contamination, pesticide resistance in target pest populations, phytotoxicity in crop fields, and unacceptably high levels of carcinogenic residue in our food supply.

We believe it is time we reclaim natural ancient ecological practices to ensure our sustainable sovereignty. Diverse ecosystems experience far fewer problems than mono-crop sites for a variety of reasons. Companion planting is one simple, low-cost, and accessible tool we can employ to boost crop yields, reduce weeds and pests, maximize nutrient density in our food, all while ensuring biodiversity in our gardens and our planet.

Companion planting — intercropping more than one species which are known to work in symbiosis, rather than competing for resources.

The mechanisms by which this technique work are numerous and interwoven.

Nutrient provision: The Three Sisters Garden utilizes this mechanism by planting legumes (beans) near corn. Legumes provide nitrogen to neighboring plants by fixing nitrogen from the air with symbiotic bacteria in their root nodules. This enables nearby plants to utilize the nitrogen and produce more protein which causes them to grow more efficiently. Corn is a heavy nitrogen feeder, so the beans assist the corn. The corn stalks provide physical structure and trellis for the beans to grow on, and the squash’s broad low growing leaves provide shade to the soil, ensuring moisture retention.

Pest suppresion: The volatile oils of some flowers and herbs deter pest species, as is the case with mexican marigolds and nasturtiums which deter many species of aphids as demonstrated by this study. Onions and carrots are often planted together using the same means, as their odors deter each other’s pests.

Host-finding disruption: According to S. Soloneski and M. Larramendy in Weed and Pest Control, “it can be more difficult for specialized herbivores to ‘find’ their host plant against a background of one or more non-host species.” Diverse plantings also provide a broader base of resources for pests to exploit, both in terms of prey species and resources such as pollen and nectar. This mechanism also encompasses the “trap cropping” technique where alternative food sources for pests are planted away from the main crop. For example, some species of caterpillar, which feed primarily on members of the Brassica family, will also eat nasturtium flowers, so planting these around cabbages will divert the pests away from the cabbages to the flowers instead, “trapping” them.

Predator recruitment: Companion planting may also recruit higher populations of beneficial insects which work to control harmful pests. This also encourages pollination which boosts crop yield.

Protective shelter: As is employed by food forest type gardening, some crops are grown under the protective shelter of other plants and trees to provide wind breaks or partial shade.

Companion Planting Champions

Basil + Tomatoes. Basil repels thrips and also deters moths which lay tomato hornworms. Basil also is bee friendly, which assists in pollination and tomato yield.

Garlic’s strong scent deters many unwanted insects including aphids, onion flies, ermine moths, and Japanese beetles. Plant garlic between rows of potatoes, alongside lettuces, cabbages, and near fruit trees, together with alyssum to attract aphid-eating hoverflies.

Mint. Rich in volatile oils, deters aphids, ants, and flea beetles. Mint is an aggressive grower, so consider potted plants for this one!

Nasturtiums attract caterpillar and keep them away from brassicas (cabbage, broccoli, kale, and other descendants of wild mustard).

Parsley attracts beneficial pollinators. Plant near tomatoes and other flowering plants like cucumbers and zucchini.

Sunflowers provide structure and shade for beans and other climbers like cucumber.

Tansy is loved well by ladybugs and repels cutworms which plague carrots, celery, cabbage, and asparagus.

Calendula is also great for attracting beneficial pollinators, and its flowers make a skin nourishing infused oil or salve.

Find out more:

Farmer’s Almanac Companion Planting Guide

The effect of fractionated Tagetes oil volatiles on aphid reproduction; B. Tomova, J Waterhouse, J. Doberski.

Weed and Pest Control: Conventional and New Challenges; By: Sonia Soloneski and Marcelo Larramendy