companion planting

Companion planting is a legendary and ancient art that is part of comprehensive garden planning. Defined as the selection of certain crop combinations to achieve specific benefits like pest control and enhanced growth, it is a great way to save space and obtain bountiful, healthy harvests.  

For example, planting broccoli, lettuce and potatoes is ideal: as the broccoli matures, it shades lettuce from full sun, and as the lettuce begins to fade, the potaotes begin to reach maturity. As a root crop, potatoes dig further into the soil and do not interfere with the surface rooted lettuces and sturdy broccoli. Potatoes and lettuce have shown through research to thrive when planted next to each other, and lettuce can even camoflauge other green plants to keep away pests.

It’s amazing but true that several different crops will influence the life-cycle and success of other crops–a fact which has been increasingly recognized in scientific circles during recent decades. Companion planting was long scorned as hippie folklore by scientists and top agricultural influencers, mostly due to the importance placed on single crop agribusiness: raise monoculture crops, supply nutrients with fast-acting chemical fertilizers, and control pests with insecticides. Well, we all know where that has lead (and is leading) us, so researchers decided to take a serious look at the relationship between climate, crops and animals. They discovered that companion planting offered numerous benefits that overrode the negative effects of monoculture farming.

 coffee and tomatoes

Plants do care who lives next door, the practice of which has now been recognized as a fledgling science by major agricultural research centers and top gardeners. Proof of intercropping, where two or more supplemental plant varieties are planted in the same field, can be found in archeological records from prehistoric Europe, Asia and the Americas, signifying its importance in maintaining healthy soil and raising a variety of edibles in small spaces with limited nutrients and water. Through trial and error, farmers, gardeners and researchers have come to discover which plants complement and even benefit each other without competing for light, water and soil nutrients.

A fantastic chart for companion planting can be found here. It will advise you on how to grow mint and repel aphids, plant marigolds to stave off Mexican bean beetles, grow leeks to keep away carrot flies or raise petunias to discourage potato bugs. How does this work? Plants have perfected very sophisticated chemical processes that allow them to fight back with pretty powerful weaponry. A small piece of plant tissue contains much more than just nutrients and water, as insecticides, fungicides, antivirants, antibiotics alongside several other defense substances, create the chemical make-up of a particular plant. Not only can plants secrete these substances, but they can also control the amount and strength of their release. You couldn’t ask for a more efficient and low-maintenance garden helper. An in-depth guide to companion planting can be found in Anna Carr’s book Good Neighbors: Companion Planting for Gardeners.

companion planting

Companion planting supports plant diversity, which is beneficial to the gardener, the soil and the ecosystem, as it feeds the variety of its environment. Plant diversity fosters insect diversity, which seems to decrease the overall number of pests and increase the number of beneficial insects and parasites. However, intercropping the wrong species can lead to problems that cause your plants to suffer. Some plants can even release toxic substances that control the soil around them so that certain other plants cannot grow nearby. To avoid this type of nasty neighbor situation, make sure to research companion plants for your crops before planning your garden. If you’ve noticed problems with certain crops from previous seasons, such as particular pests or poor yields, find out which plants help fight those pests or retain certain nutrients that particular crops thrive on.

Keep in mind that companion planting is not the solution for any gardening problem, but can act as an extremely effective preventative measure. A garden is a web of life that is much more complex than just a bunch plants and bugs – they definitely have a social life. Appreciate this sophistication and elegance by observing the effects of your helping hand and enjoying the bounty that ensues. 

Images: Myrtle Glen, CIAT