Sustainable Gardening Strategy: An Introduction to Companion Planting

One of the secrets to successful organic and sustainable gardening is something called companion planting.  When you wish to avoid chemical herbicides and pesticides, or they aren’t allowed, as they wouldn’t be if you’re gardening organically, then companion planting is an excellent solution.

What is Companion Planting?

Some plants give off scents or chemicals that repel insects, insects like worms and beetles that can destroy your garden.  Other plants help prevent disease or attract insects, which are beneficial to plants. And some plants are exceptional at breaking down the soil and helping other plants absorb vital nutrients.  Essentially companion planting is used to help your core plants thrive without chemicals. 

Companion planting of carrots and onions (Photo credit: Wikipedia)

Examples of Companion Planting and How it Works

Marigolds are widely known to have a very strong fragrance.  Many people consider it unpleasant despite the gorgeous flowers. However, many insects also find marigolds quite distasteful including nematodes (roundworms), whiteflies, beetles, and aphids.  To use marigolds as a companion plant, plant them at the perimeter of your garden.  If your garden is large you may want to plant them throughout.  Take care to not plant them too closely to your vegetables because they do attract spider mites and slugs. 

Alfalfa actually helps the soil absorb nitrogen, iron, magnesium, phosphorous and potassium which makes the soil ideal for growing vegetables.  Because alfalfa has very long and sturdy roots, it breaks up hard clay soil. It’s a great plant to help keep your soil rich in nutrients. 

Geranium, another flower with a strong aroma, repels cabbage worms and Japanese beetles, and leafhoppers.  Gardening experts recommend planting them around grapes, corn, tomatoes, peppers and cabbage.

Companion Plantings (Photo credit: Wikipedia)

Deciding What to Plant and Where

Before you begin planting your organic garden, do a bit of research to find the best placements for your chosen vegetables. For example, tomatoes do well with a number of other vegetables including garlic, chives, cucumber and mint, however not all veggies get along with tomatoes.  Tomatoes can stunt the growth of carrots and dill, and kohlrabi slow tomato growth. 

Make a quick map of your garden before planting and chart where you want to plant each vegetable.  A quick trip to an organic gardening or companion gardening site will help you make sure each vegetable’s neighbor is a helpful one.

Companion planting is a very sustainable way to affect the health of your garden.  Not only do you help your garden stay pest and disease free, you receive the added benefit of a diverse and healthy garden - which means more tasty and healthy veggies for you!

Note: For some great detailed suggestions on companion and succession planting, see the excellent books below.