11 Vegetables You Should Never Plant Together
Not all vegetables grow well together! Some combinations are harmful, causing poor growth in both crops. Know which ones go together and which ones don’t, and you’ll never make a pairing mistake again. Join seasoned grower Jerad Bryant in discovering these 11 vegetables you should never plant together.
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Companion planting is essential in home gardens! When you pair beneficial vegetables together, you help each kind grow better than it would alone. Famous pairings like basil and tomatoes, marigolds and peppers, and lettuce and radishes are iconic in the gardening world.
Other pairings are more harmful than beneficial! If you had poor yields at harvest time, chances are you grew two crops near each other that should have grown separately. Knowing which vegetables to avoid planting together is a useful skill that’ll help boost your future harvests.
So, without further ado, here are tried-and-tested vegetable combinations you should never plant together. Split them with containers, separate beds, or individual planters.
Beans and Onions
Beans love growing up corn stalks, next to celery, and among cucumbers. They dislike maturing next to onions and onion relatives like shallots, garlic, and scallions. The onions have an inhibitory effect on bean plants, causing them to grow slowly and poorly during the summer.
Both pole and bush beans dislike onions. Consider planting your onion crop away from the bean bed. Keep the roots of the two crops in separate spaces, and avoid planting their seeds near each other. You may plant a few leeks next to beans, but try not to overdo it. Consider alternative companions for beans such as marigolds, celeriac, or beets.
Beets and Mustard
Beets are earthy, tasty, and nutritious root vegetables that have a wealth of beneficial companions. Though they pair well with beans, kohlrabi, and onions, they vehemently dislike growing next to mustard. Give these two plenty of space.
Kohlrabi and beets have similar nutritional needs, and they grow in slightly different ways that complement each other. The beets form large, bulbous roots underground, while kohlrabi vegetables form thick, bulbous stems aboveground. They’ll appreciate the same fertilizing, cultivating, and harvesting regimens in home gardens.
Broccoli and Tomatoes
Broccoli, like other cole crops in the cabbage family, has a litany of vegetables it won’t grow well next to! Tomatoes are one of them. You’ll also want to avoid planting broccoli with pole beans and strawberries. Pole beans and tomatoes shade out the plants, while strawberries draw nutrients from the soil that broccoli plants need in high quantities.
For the best results, cultivate broccoli with vegetables like beets, onions, and potatoes. Situate tomatoes far from the broccoli bed, and regularly fertilize both crops for the largest yields come harvest time.
Cabbage and Strawberries
Vegetables in the same family have similar needs, dislikes, and growing preferences. Cabbage is in the cabbage family, like broccoli, collards, mustard, and kohlrabi. These plants dislike growing next to tomatoes and strawberries.
When cabbage grows next to strawberry crops, cabbage loopers may find their way into the red fruits. Cabbage loopers are green caterpillars that are the larvae of a brown moth. They’ll quickly make a meal of your plants, turning full leaves into skeletons with only their ribs remaining.
Not only do strawberries compete with cabbage, but they’re also unruly in beds with other plants. They sprout runners that grow new rosettes far from the original plants. For best results, give strawberries their own bed or grow them in planters and containers to limit their spread.
Cucumbers and Potatoes
Cucumber lovers should plant potatoes far from the vines. The two vegetables interfere with each other, attracting pests and diseases to the site. Cucumbers near potatoes are more likely to face blight infections than those growing alone.
Blights are nasty fungal conditions that affect both potatoes and cucumbers. They spread throughout the plants, causing wilting leaves, limp stems, and dead plants. Situate these two vegetables on opposite ends of your garden.
Plant cucumbers next to friendly companions like beans, peas, radishes, and sunflowers. Or, to save space, place cucumber vines on a trellis and train them upwards.
Melons and Potatoes
Melons grow off of long, rambling vines with large, lobed leaves. They shade the ground as they grow, covering wide swaths of the garden. Potatoes require constant hilling and trenching, which is difficult to do if there are melon vines in the way.
Rather than pitting these two vegetables against each other, consider planting them with favorable species that complement their growth. Corn and sunflowers are perfect for melons, as they grow tall above the vines below. Try vegetables like lettuce or garlic next to potatoes.
Peas and Garlic
Peas grow readily with most other vegetables, though they particularly dislike sprouting near garlic and onions. Garlic may stunt pea plants’ growth, causing short, pod-less plants that attract pests and diseases.
Instead of garlic, plant peas alongside herbs, corn, and beans. Pea roots partner with bacteria that convert gaseous nitrogen into a form that plants can use. In this way, planting peas helps increase nitrogen levels in the garden’s soil. This process, called nitrogen fixation, also benefits plants like turnips, cucumbers, and potatoes.
Tomatoes and Fennel
Fennel is a large, fern-like plant with lacey, fringey foliage. It forms a large bulb above ground that’s full of licorice flavor. Though it’s useful in the kitchen, it’s not a friendly plant for tomatoes. The two compete for nutrients and sunlight, causing poor growth in both crops. Broccoli, cauliflower, and other cabbage family members are similarly detrimental to tomato plants.
Instead of fennel or vegetables in the cabbage family, grow tomatoes close to green beans, peas, and asparagus. Train them on a trellis to manage their rambling stems and heavy fruits.
Tomatoes and Potatoes
Tomatoes have a few honorable mentions here, simply because they’re incredibly popular and versatile! Most gardeners grow them, even if they don’t call themselves a vegetable gardener. Because of their popularity, famous foes like potatoes are common knowledge amongst longtime growers.
Potatoes and tomatoes are members of the same family, meaning they share a fair number of pests and diseases. They also use similar nutrients, meaning they’ll require extra fertilizer during the growing season.
Tomatoes and Corn
Corn and tomatoes attract the same pest, the corn earworm. Also known as the tomato fruit worm, this pest bores into tomato fruits and corn ears, causing misshapen harvests. After they form tunnels, they leave open wounds that invite molds, fungi, and bacteria to cause further havoc in your garden.
Keep corn far away from your tomatoes. Corn grows well with beans, peas, and squash. The upright stalks provide support for vining vegetables like beans and peas.
Watermelon and Corn
Unlike other melons, watermelon vines need as much sunshine as they can get! Tall corn stalks shade the foliage, leading to low yields and small watermelons. Give your watermelon vines plenty of space to ramble—some varieties will extend 20 feet or longer!
Potatoes are good candidates for growing under watermelon vines. The rambling stems provide afternoon shade for the potato plants, keeping them cool in the middle of summer.
