Skip to main content
You are the owner of this article.
You have permission to edit this article.
Companion planting can help control insects and disease

Companion planting can help control insects and disease


Although our spring weather has been beautiful, cooperative and breezy, it has only recently started to get warm. I’ve incrementally added plants into my vegetable garden, as many things just aren’t happy until the soil temperature rises. This slow transition from cool to warm has allowed me time to implement more companion planting practices into my garden.

The concept of companion planting is nothing new, but I do think it’s a practice that is under-utilized. Companion planting is the simple act of planting certain crops with or near one another to achieve better yields and/or healthier plants. Companion plants can benefit one another by controlling insects and disease, serving as physical supports, or improving flavor of food.

It’s important to remember that there are good and bad companions. It’s knowing the difference that can create good relationships in our gardens.

One of the most versatile and best companion plants is basil. All gardening books list this pungent annual herb as a companion for a host of vegetables — especially tomatoes and peppers. When planted near tomatoes and peppers, basil is said to increase the flavor of both. There’s much debate as to the validity of that claim, but one thing holds true — basil is a natural insect repellent, which can keep harmful insects away from tomatoes and peppers. And plants that aren’t wracked by damaging insects will produce better fruit.

Basil, of course, thrives in heat and just isn’t happy in the garden until we start to get consistent summertime weather. So with warmer weather settling in, I’ve been sprinkling more and more basil throughout my beds. Not only will this provide good companions throughout my garden, but I’ll be working toward periodic harvests of basil to make pesto.

Tomatoes are one of the most commonly planted crops,and they have good and bad companions. Planting tomatoes near your asparagus bed is beneficial to both parties involved. Tomatoes produce solanine, which is toxic to asparagus beetles. Asparagus is said to produce a substance that deters nematodes, which can damage tomato roots. These two crops hit their peak of production during different seasons, but they can still boost each other just by being close.

Other good tomato companions include borage, calendula, marigolds, parsley and onions. Borage is said to repel tomato worms; chives, onions, calendula and marigolds are said to drive away pests; and parsley is supposed to improve the flavor of tomatoes.

Fennel, potatoes and crops in the brassica family (cabbage, broccoli, etc.) are considered bad tomato companions. Fennel roots contain a substance that inhibits the growth of tomatoes and other garden crops. Potatoes encourage blight and disease, and brassicas are said to stunt the growth of tomato plants.

Companion planting also can be utilized for structural and design purposes in the garden. Perhaps the most well-known version of this is the three sisters garden.

Traditionally used by some Native American tribes, the three sisters garden combines corn, beans and squash. Corn is planted first, pole beans are planted at the base of the corn, and squash is planted between the corn. The corn will grow tall and strong, the beans will use the corn as a trellis, and the squash will shade the roots, retaining moisture and discouraging weeds.

Also popular are edible flowers and trellised vegetables. Nasturtium is a perfect edible flower, which can pair nicely in the garden with vining cucumbers. Try planting a mix of nasturtium at the base of your cucumber trellis, as this is beneficial for pollinating insects and helps to create shade for your cucumber roots.

Perhaps the best companions you can introduce to your vegetable garden are perennial and annual pollinator plants. The addition of blooming flowers to your garden will draw in a wealth of pollinating insects, which will increase your yields and greatly benefit your backyard ecosystem. Annual sunflowers can be easily planted around the perimeter of a garden, and zinnias and cosmos are great for planting directly into vegetable beds.

This past year I cultivated a new bed right outside my vegetable garden gate, where I’ve planted herbs, native perennials and lots of pollinator plants. This bed serves as a great way to plant clumping perennials that I don’t have room for in my veggie beds.

Although there hasn’t been much scientific study to back up claims of certain companion planting, generations of gardeners have relied on these methods. As a child, my seasoned gardener elders reminded me often of the importance of marigolds in the garden — illustrating how trial, error, observation and experience can teach us a lot.

I encourage you to try your hand at companion planting. Even if it’s just dotting basil throughout your veggies, it’s a great way to get the most out of your garden.

Amy Dixon is an assistant horticulturist at Reynolda Gardens of Wake Forest University. Gardening questions or story ideas can be sent to her at or, with “gardening” in the subject line. Or write to Amy Dixon in care of Features, Winston-Salem Journal, 418 N. Marshall St., Winston-Salem, NC 27101

Be the first to know

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Related to this story

Get up-to-the-minute news sent straight to your device.


Breaking News