Ask a Master Gardener: How companion planting can benefit your garden

Anyone that has ever shared a room with a sibling or roommate knows only too well that you've all got to get along for happiness and health to prevail.

Well, it is the same with garden plants, too!

In the garden, plants interact with each other to create an atmosphere for growth.

Every plant has an effect on every other plant. Companion planting is based around the idea that certain plants can benefit others when planted next to, or close to, one another.

Over time, gardeners have observed these interrelationships and scientists have studied them. Plants are not timid, they are always actively engaged in growing as fast and as strong as they can to re-populate their species.

The companion effect happens naturally in the wild. It may seem like survival of the fittest, but the truth is some species prefer to grow with specific others, balancing out their differences and providing ideal conditions for optimizing their unique traits.

Plants don't like to fight for their food, so shallow rooted plants prefer to grow near deep rooted plants so each can get their nutrients from different levels.

Some smaller plants like a bit of weather protection from bigger plants. Conversely, dry-loving plants will not do well if grown alongside plants that thrive with wet feet.

Home gardeners of course usually like to grow their food on as much available space as they can. They don't want weeds, pests or sometimes even ornamentals occupying valuable real estate!

But flowers, for example, make good companion plants, as well as adding beauty. They can attract predators to go after pests and they bring bees to your garden for pollinating your fruit.

Aromatic flowers and herbs help confuse hungry pests that might go after your crops. Their fragrances can distract pests away or mask the odor from the pests' normal favorite plants.

For example, Zinnias attract ladybugs so when planted near cauliflower, which is susceptible to cabbage flies, the ladybugs are there to control the pest population.

This spring while you are planting your garden, keep these things in mind.

Dill and basil planted among tomatoes protect the tomatoes from hornworms, and sage planted in the cabbage patch reduces harm from cabbage moths.

Marigolds are as good as gold when grown with just about any garden plant, repelling beetles, nematodes, and even animal pests.

Nasturtiums are so favored by aphids that the devastating insects will flock to them instead of other plants.

Carrots, dill, parsley and parsnip attract garden helpers like praying mantises, ladybugs, and spiders that dine on insect pests. Although carrots, dill, and parsley like the same bugs, they don't necessarily like each other so keep them separated in the garden.

Of course, like I just mentioned, not everyone in the garden gets along.

Although garlic and onions repel a number of pests and make excellent neighbors for most garden plants, the growth of beans and peas is stunted in their presence.

Potatoes and beans grow poorly in the company of sunflowers. And although cabbage and cauliflower are closely related, they don't get along with each other that well.

Consider also that too many of the same plants, or plants from the same family, create a monoculture in the garden which makes your plants more susceptible to invasion by pests and diseases.

Adding diversity to your garden space through the planting of good companions helps to naturally ward off pests and diseases, sometimes without the use of harmful chemicals or pesticides.

One of the keys to successful companion planting is observation. Record your plant combinations and the results from year to year, and share this information with other gardening friends.

Companionship is just as important for gardeners as it is for gardens.

Now, after I said all that, don't get stressed out about it. Gardening is suppose to be fun. There have been many a time that I got the garden all planted and sat down in my lawn chair, only to notice some bad combinations or some new combination I wanted to try and forgot.

Did it make a difference? I don't know. Seems I usually over-plant anyway.

Happy gardening!

Peter Sutter is a lifelong gardening enthusiast and a participant in the MU Extension's Master Gardener program. Gardening questions can be sent to [email protected].

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