The Art of Companion Planting, Part 2: Vegetables and Herbs

With the right placement, garden plants can protect each other from pests and disease while boosting growth, doing much of the hard work for you

Tomato plants pair well with herbs, particularly basil and thyme.Digihelion/Shutterstock

Think of your garden as a family, and plant it similarly to seating guests at a Thanksgiving dinner (which will hopefully feature some of your fall harvest!). You can seat Aunt Samantha anywhere and she’ll liven up the table. You want to put Aunt Olivia near the nieces she never gets to see so they can all catch up and have the best time possible.

At the same time, you might want to seat those relatives with equally passionate yet widely different political views far apart.

It’s the same with plants. Though tomatoes and potatoes are both in the nightshade family, they should never be planted together, as they share the same pests and diseases, which can be easily spread between them and decimate both crops. In fact, they shouldn’t even be planted one after another, for the very same reason. Yet both benefit from hanging out with onions and garlic, which repel their most popular pests. Intrigued?

Zucchini and other squashes benefit from close proximity to radishes, beans, and legumes.Cineberg/Shutterstock

Tomatoes

Top gardeners swear that planting basil next to tomatoes will give you more flavorful tomatoes. While this has never been scientifically proven, studies have shown that tomatoes planted next to basil tend to yield more fruit. Even if you don’t have space for a garden, you can liven up summer meals by growing these two together in a container just about anywhere that gets eight hours of sunlight.

Tomatoes love most scented culinary herbs, particularly thyme, whose scent helps them hide from armyworms; asparagus, as it helps repel nematodes; borage, which repels hornworms; garlic, which discourages spider mites; and beans, which add nitrogen to the soil.

As already mentioned, keep the potatoes away. Also avoid members of the brassica family: cabbages, mustard plants, broccoli, cauliflower, Brussels sprouts, collards, and most definitely kohlrabi, all of which can stunt the growth of other plants.

Squash and Spice

Zucchini and their cousins in the highly prolific squash family like to be situated by radishes, which deter squash vine borers, and dill, which attracts lacewings and ladybugs, which eat squash bugs. Beans and legumes will fix nitrogen in the soil, and borage will repel common pests and add calcium to the soil.

Keep the brassica family members away, as they’re a magnet for cabbage worms, cabbage moths, and aphids, as well as potatoes, which will hinder growth.

Peppers are on most gardeners’ “Top 5” list. Peppers’ best buddies list, in turn, includes basil for the flavor boost, carrots to act as a living mulch, Swiss chard for wind protection and shade, spinach for weed control, and onions and garlic to ward off cabbage worms, slugs, aphids, and many other garden pests.

Never plant peppers near cauliflower, kohlrabi, broccoli, cabbage, kale, Brussels sprouts, fennel, or apricots; they’ll either compete for water and nutrients or attract destructive pests.

Corn is a good companion plant for pole beans and cucumbers to climb, and it pairs well with potatoes.lovelyday12/Shutterstock

Beans, Peas, and Cukes

Beans are a favored garden choice not only for their ability to provide a nutritious side dish, but also for their ability to add nitrogen to the soil. They do well with celery, as it helps prevent soil-borne fungal diseases, and with rosemary, summer savory, and potatoes, which help trap and repel bean beetles.

Pole beans love to climb corn. Bush beans love beets—but beware, they can retard the growth of pole beans. Always keep the onions, leeks, garlic, and peppers far away from both types of beans.

Peas have similar growing requirements to green beans’, and they grow well together. They also benefit from turnips, which repel aphids, and basil, which deters the thrips that thrive in the flowers and developing pea pods. Plant all members of the onion and garlic family in another area of the garden, otherwise they’ll stunt the peas’ growth.

Another popular climber, cucumbers, will benefit from proximity to beans and peas and the nitrogen they add to the soil. Cucumbers also benefit from being placed near corn, which they will happily climb. Dill attracts parasitic wasps that prey on cucumber pests, and oregano’s odor is offensive to aphids and other sap-sucking pests. Unlike most other garden plants, cucumbers don’t like the aromatic herbs sage, mint, and basil.

Potato Partners

By now, you’re probably thinking that, with a few exceptions, potatoes need to be grown in a world of their own. That’s not true. The brassicas family loves them because brassicas have shallow roots and potatoes’ roots go deep, meaning they won’t compete for nutrients, and together, they are a great way to make the most use of garden space. Corn is in a similar situation, as it grows up and potatoes grow down.

Chives are not only great for topping a baked potato; they also attract beneficial insects. Cilantro also attracts beneficial insects, in particular those that prey on Colorado potato beetles. And flax repels beetles with its tannin and linseed oils. Horseradish both repels beetles and improves the potato plant’s disease resistance. Leeks grow well near potatoes, as do peas and beans.

Companion planting is all about making your garden work for you.

More Good Neighbors

Although it’s not possible to include every type of garden plant and the multitude of resulting combinations in one article, none would be complete without the ABCs.

Asparagus

Plant tomatoes next to asparagus, particularly in its early years, to help deter asparagus beetles. Also grow alongside some basil for added protection. Eggplant repels both asparagus beetles and nematodes. Strawberries make an excellent groundcover.

Brassicas

When grown with chickpeas, brassicas (cabbage, cauliflower, broccoli, Brussels sprouts, etc.) produce a larger harvest. Broccoli grows taller when planted with radishes. Mint prevents flea beetles, and fennel keeps down aphid populations.

Carrots

Carrots adore chives, which improve their flavor and growth and repel pesky aphids, mites, and the carrot rust fly. Rosemary, sage, and leeks also ward off the carrot rust fly. Beans add nitrogen to keep the soil healthy.