Companion Gardening

By Jon Whitinger

Last Updated - 4/13/2023


Companion gardening is an age-old practice that involves planting different kinds of plants together to create a mutually beneficial environment. This approach maximizes space utilization, improves plant health, and increases crop yields. Let’s dig into the world of companion gardening, discuss its advantages, and showcase some of the most effective plant pairings for your garden.

One of the main advantages of companion gardening is that it promotes a natural ecosystem in your garden, which encourages biological diversity. Planting different species together helps create habitats for various beneficial insects, aiding pest control. Moreover, certain plants can enhance the soil's nutrient content, supporting their neighboring plants' growth and development.

Herbs are a valuable addition to any companion garden and offer numerous benefits. For instance, basil is an excellent companion for tomatoes, as it repels harmful insects and may enhance the tomato's flavor. Similarly, rosemary, sage, dill, cilantro, and oregano can deter pests like cabbage moths, making them excellent companions for brassicas such as broccoli, cauliflower, and cabbage.

Other vegetables can also benefit from companion gardening. Some classic combinations include carrots and onions, where the strong aroma of onions masks the carrot scent and prevents carrot fly infestations. Another example is lettuce and radishes, where the quick-growing radishes can be harvested before the lettuce needs space, allowing for efficient use of space and reducing competition for nutrients.

The Three Sisters is an ancient companion gardening method famously used by Native Americans, consisting of corn, beans, and squash planted together. Corn acts as a natural trellis for the beans to climb, while the beans fix nitrogen in the soil, which nourishes the corn. The squash, with its large, sprawling leaves, shades the ground, helping to conserve moisture and suppress weeds. This combination is not just productive but also nutritionally balanced, providing carbohydrates, proteins, and vitamins for a healthy diet.

Marigolds are another popular companion plant, thanks to their ability to repel various pests. The bright flowers contain a chemical called alpha-terthienyl, which is toxic to many insects and nematodes. Marigolds can be interplanted with vegetables like tomatoes, peppers, and eggplants to help deter pests and enhance overall garden health.

Nasturtiums are also a useful addition to companion gardens, as they are a “trap crop”, attracting aphids and other pests away from more valuable crops. They can be grown alongside vegetables such as beans, tomatoes, and cucumbers to provide a sacrificial decoy for harmful insects. Flowers such as Alyssum, dill, cosmos, and yarrow attract beneficial insects such as spined soldier beetles that feed on aphids.

Another beneficial companion plant is borage, which can deter tomato hornworms and cabbage worms while attracting beneficial insects like bees. Chamomile enhances the growth and flavor of nearby plants like onions, cabbage, and cucumbers.

Growing cover crops during the winter has been proven to assist with weed and disease management as well. Sowing a cover crop of Annual Rye, Austrian Winter Peas, or Crimson Clover during the colder months and tilling them under before planting your vegetables is a great starting point. Hairy Vetch is a highly effective cover crop to precede tomato planting. Sow the vetch in autumn and cut it down in spring, using the plant material as mulch beneath the tomato plants. This can help mitigate leaf blight diseases on your crops.

It's important to note that not all plants are suitable companions. Some combinations can stunt growth or attract pests. For example, planting beans near onions can inhibit the beans' growth, and tomatoes should not be grown near potatoes, as they can attract the same pests and diseases.

Don’t be afraid to mix things up! Gardens are living things, and a garden with a big diversity of plants all bunched together is often much more healthy than monocultures of the same crop planted in boring rows. 🙂