:strip_icc()/GettyImages-1682634482-8f8cbb5a81bd44be90cdae7b67e6225e.jpg?w=1920&resize=1920,1267&ssl=1 "10 Watermelon Companion Plants to Boost Your Harvest (Plus 3 to Avoid)")
Watermelons thrive in rich soil and full sun, producing harvestable melons just 70 to 100 days after planting. While watermelons are relatively easy to grow, their sprawling vines and high nutrient needs make them tricky to keep with other crops. Fortunately, several plants can keep up with the vigorous growth of watermelons. This list contains 10 of the best watermelon companion plants, plus a few plants that should never be grown near watermelons.
Sunflowers
Bob Stefko
With their fast growth rate and tall stems, you don’t need to worry about sunflowers being drowned out by watermelons. That’s not the only reason to grow sunflowers and watermelons together. Sunflowers are also highly attractive to pollinators and other beneficial insects that pollinate watermelon flowers and feed on melon pests.
Culinary Herbs
As long as you follow proper spacing guidelines, most herbs grow well beside watermelons, and they’re some of the best companion plants for natural pest control. Basil, dill, catnip, sage, and oregano make particularly good watermelon companion plants, either because they attract predatory insects or repel watermelon pests, like cucumber beetles. If you allow herbs to flower, they entice pollinators to visit watermelons and potentially increase the size of melon harvests.
Corn
Bob Stefko
One of the oldest examples of companion planting is the Three Sisters planting method, in which winter squash is grown with corn and beans. In this planting design, the large squash leaves act as a living mulch that keeps weeds from sprouting beneath the corn plants. However, watermelons can be substituted for the winter squash to put a new spin on an old planting classic. Keep in mind that corn and watermelons are both heavy feeders, so it’s doubly important to build your soil with compost and fertilize your plants regularly during the growing season if you keep these plants together.
Borage
David Speer
Borage is often overlooked as a companion plant, but it’s one of the best plants to grow if you want to attract pollinators and other beneficial bugs. There is even some evidence that borage can make neighboring plants, including watermelon, more resistant to pests and disease. Plus, borage leaves and flowers are edible and can be used to garnish plates of sliced watermelon or bowls of watermelon salad at summer picnics.
Beans and Peas
Marty Baldwin
Like corn, legumes such as lentils, peas, beans, chickpeas are included in the Three Sisters planting method because of their ability to fix nitrogen into the soil. This quality means that if you grow watermelons near legume plants, legumes contribute nutrients to the soil that help watermelon vines grow better. To avoid plant competition, choose pole-type legumes, like purple podded pole beans, and grow them on a trellis so they won’t need to compete with watermelons for soil space.
Radishes
Marty Baldwin
Watermelons are heat-loving crops that can’t be planted outdoors until the danger of frost has passed. However, you can get more use out of your garden and grow more edibles in a small space by planting some cold-tolerant spring radishes in your beds when temperatures are still too chilly for watermelons. When warm weather arrives, you can harvest the radishes and free up your soil space for watermelon seeds at the same time.
Plant radishes in full sun in well-drained soil—they rot in soggy, poorly drained soil.
Mint
Jason Donnelly
Mint is a notoriously aggressive plant that crowds out most other crops, but sturdy watermelon vines shouldn’t be bothered by vigorously growing mint as long as you give both plants enough space to spread out. Best of all, the scent of mint repels an assortment of watermelon pests, including flea beetles and aphids, and mint and watermelon pair beautifully together in recipes, like watermelon, feta, and mint salad.
Alliums
Garlic, onions, leeks, chives, and other alliums exude a strong fragrance that repels most pests, including aphids and slugs that may damage watermelon crops. Alliums also take up minimal space and are easy to slip in between watermelon vines. If you want to try your hand at DIY pest control, you can also brew allium leaves in water and make a natural fungicide for treating the powdery mildew that sometimes affects watermelon leaves.
Nasturtiums
Nasturtium flowers attract pollinators and beneficial insects that feed on watermelon pests, but nasturtiums can also be used as a trap crop to draw aphids and other pests away from watermelon plants. For best results, choose trailing nasturtium varieties, which tend to get along better with watermelons than mounding-type nasturtiums.
Watermelon Companion Plants to Avoid
Although plenty of companion plants can be grown with watermelons, some plants don’t get along with melons. Here are three types of plants to keep far away from watermelons if you want healthy plants and big harvests.
- Other Cucurbits. Squash, cucumbers, pumpkins, and other types of melons are heavy feeders that may steal nutrients away from watermelons and make melon harvests less impressive. Even worse, cucurbit plants are vulnerable to many of the same disease problems, and can attract more pests to your watermelon plants.
- Potatoes. Spuds also need a lot of nutrients to grow well, and they can suffer if heavy-feeding watermelons are nearby. On top of that, potato plants do most of their growing underground and may compete with watermelons for soil space.
- Fennel. This aromatic plant releases allelopathic compounds into the soil, keeping neighboring plants from competing for soil space. Even vigorous watermelons can be affected by these compounds and may produce smaller harvests or stop growing if fennel plants are around.