As plans are being prepared for our gardens, most of us think about the layout, considering each plant type separately.  The planning generally looks at the amount of space needed and the amount of sunlight required by the plant as decisions are made about where to position plants.

However, many of us do not take into account how various plants interact with each other, a concept referred to as “companion planting.”  Companion planting considers how to enhance the garden or impact plants by growing them in close proximity to each other. Companion planting has the potential to enhance your garden, reduce the need for pesticides, promote stronger plants and take maximum advantage of the space available.

Companion planting is not a new concept.  It is a tool used in organic gardening and has been used historically by indigenous people.  Research has identified varying results regarding the benefits of specific companion plantings.  There is only anecdotal evidence of the benefits of overall companion planting.  But there are numerous reputable articles on how to incorporate the concept into our gardens.

In this article I will identify six potential benefits of companion gardening, using a relatively broad definition of companion gardening.

1.     Repelling Pests

Consider planting plants that repel pests next to plants that the pests target. According to an article in the University of Arizona Agriculture and Life Sciences Cooperative Extension site: 

One of the most accepted wisdoms of companion planting is the use of repellant plants to keep bothersome insects away from their favorite vegetable plants. Insects locate their favorite plants through smell and many repellant plants work by masking the scent of their neighbor plants. That is why strong-smelling plants such as basil, onions, garlic, and marigolds are good reliant plants.[1]

2.     Attracting Beneficial Insects

Conversely, companion planting might be used to attract beneficial insects.  The best example of this is the suggestion that a gardener plant flowers that will attract pollinators next to vegetable that will benefit from these insects. Companion planting can also be used to attract insects that will feed on destructive insects.  For example one might grow plants, such as carrots, to attract lady bugs that will feed on aphids that might attack

your plants.

3.  Growing Sacrificial Plants

A sacrificial crop is a plant that you add to your garden to attract pests away from the main crop you are growing.  The reasoning is that garden pests have preferences for what they like to live on or eat.  By planting rows of sacrificial plants near your preferred vegetables, the pests will be attracted to these plants and leave your “preferred plants” alone.

4.  Enhancing the Taste of Edible Plants

Many people believe that planting herbs such as basil, dill, oregano or marjoram next to tomatoes and peppers may enhance the sweetness of these vegetables . . . and they also add beauty to your garden.

5. Supporting the Growing Needs of Surrounding Plants

The growing characteristics of one plant can be used to benefit surrounding plants.  For example, plants that grow tall or are supported by trellises can provide shade to plants that prefer limited sunlight.  Vining plants and plants with large leaves that cover the ground can reduce weed growth and help retain soil moisture.

6. Promoting Maximum Use of Garden Space

In this example of companion planting, you’re considering how to enhance the production of your garden as a whole.  By intercropping plants in spaces left when one crop is done producing you can increase the production from a limited space. Radishes mature quickly and do well in cooler weather so they can be planted in the spring. When they are harvested, plants that prefer warmer weather can be planted. And when those plants are done producing, another crop of radishes can be planted in late summer.

This is a link to a chart developed by Todd Weinmann of North Dakota State University Agriculture Extension that provides an extensive list of plants that you might consider growing near each other and plants that have the potential to negatively impact the growth of certain plants and therefore should not be planted in close proximity.

[1] The Best of Enemies: A Brief Guide to Companion Planting - Part 2, https://cals.arizona.edu/cochise/mg/best-enemies-brief-guide-companion-planting-part-2

Photo credits: www.flickr.com (1), Linda Stein (2), University of Minnesota Extension (3)