Companion Planting 101

So you want to start companion planting?

You’ve come to the right place! At Trees for the Future, we’ve studied farming and natural growing processes for more than three decades. One simple yet easily overlooked upgrade in growing food is companion planting. 

What is Companion Planting?

Companion planting is simply planting two or more mutually beneficial plants next to each other. Companion plants are fruits, vegetables, herbs, shrubs, or flowers that provide a benefit to their neighbor, whether that’s through nutrients, providing shade, or protection from pests or disease. This technique is an integral part of permagardening. 

A permagarden is a permanent bio- intensive garden that, once established, can protect and produce an abundance of diverse, healthy foods in a relatively small area from one season to the next for as long as it is properly managed. Diversification is key in any permagarden; planting diverse species in the same space is called intercropping. When intercropping it is important to know the characteristics of the different plants that share the same space to be sure that they will grow well together. Sets of intercropped plants that grow well together and benefit from each other are called companion plants. One of the most well-known companion planting practices is known as The Three Sisters - made up of corn, beans, and squash. The corn provides a structure for the beans to climb on. The beans provide nitrogen to the soil that the other plants need. And the spreading squash plant creates a living mulch by blocking sunlight, reducing soil temperatures and minimizing moisture loss and weed growth.

Being in Harmony with Nature means letting Nature Harmonize

Healthy ecosystems don’t grow like we plant. Typically, plants don’t naturally grow in straight lines and they are not isolated from other species. A happy garden or farm has variety, and that variety accomplishes a lot for both the land and the grower. In addition to supporting soil health and biodiversity, plants support one another. Companion planting simply recognizes those relationships and takes advantage of harmonious relationships between plants. 

Where to Start

Determine your growing space and take into account any major environmental challenges you may face: common pests in the region, soil composition, sun exposure, etc. It’s when we’re planning our crops that we may forget to lean on companion planting or forget to consider which plants are not companions at all. Plants that do not grow well together are called antagonists. 

When you’re planning your garden, make sure to consider each plant’s physical characteristics, nutrient needs, growth rates and habits before intercropping them. 

4 Tips When Starting Out

Use appropriate spacing – Be sure to use correct spacing when intercropping plants. Plants should be no closer together than the smallest spacing requirement of the vegetables being planted.

Take advantage of plants’ differences – One of the largest benefits of intercropping is that plants that have different physical characteristics can be worked into the same bed like puzzle pieces.

• Place plants with low leaf cover and compact or shallow root systems next to plants with larger leaf cover and deeper root systems.

• Mix slow-growing plants with fast-growing plants so they don’t compete. Grow plants that require lots of nutrients (heavy feeders) with those that require little (light feeders).
• Plant aromatic plants that deter pests to protect non-aromatic plants.
• Plant flowering plants with pollen and nectar that attract beneficial insects to feed on pests.
• Grow plants that attract and trap pests near your other higher-value crops
• Plant crops that grow in different ways (e.g. climbers and stalks or bushes) so that one can be supported by the other.

Work with plants from different families – In general, plants from different vegetable families are susceptible to different pests and diseases than those of other families. By diversifying vegetable families being grown in the garden, the potential for devastating insect loss is even further reduced.

Keep transplanting and seeding issues in mind – If a bed is direct-seeded it is difficult to intercrop with transplants before the seedlings sprout without disturbing seeds that are in the process of germinating. Always transplant before direct seeding OR direct seed first and then wait until the seedlings have broken the soil surface before transplanting. Your decision will rely on the growth cycles of the particular plants being intercropped.

A Cheat Sheet of Companion Plants

Click here to see and download a high resolution version of our companion planting guide. For planting guidelines and an in-depth explanation of companion planting and intercropping, see chapter 13 in the Forest Garden Technical Manual. Trees for the Future’s Forest Garden Training Center is a free and public resource.