7 Watermelon Plant Companion Plants

Watermelon plants grow best when grown near other beneficial plants. Which companion plants should you consider growing?

Watermelons are one of the most garden-friendly plants since they grow well with a variety of other plants.

Companion planting is a gardening technique that allows neighboring plants to help one another in different ways, such as by repelling harmful pests or attracting helpful pollinating insects to the area. 

Although there is no specific companion recommended plants for watermelons, there are plants that are beneficial to watermelon plants when they’re planted nearby.

1. Borage

Borage is an annual herb that is easy to grow and grows quickly. It has bright blue flowers that attract pollinating insects to the garden. This herb tastes and smells like cucumbers. 

Optimal watermelon development depends on pollinating insects like bees. Therefore, pleasant-smelling flowering plants like borage make ideal companion plants for growing watermelons.

Borage plants also repel aphids, which can be harmful to watermelon plant leaves.

blue borage plant with little thorns

2. Radishes

Radishes come in different colors and can have a spicy or peppery flavor. They have short roots and grow quickly, which makes them easy to pick when they’re ready for harvest.

It’s a good idea to plant radishes near watermelon plants before watermelons start spreading to fill any empty garden space. 

Radishes are good for controlling pests that target cucumber and watermelon plants. Notably, the striped cucumber beetle can spread bacterial wilt, which can devastate growing watermelon plants.

small and red radishes growing in the ground

3. Onions

The onion is a biennial bulb with green tubular leaves. Onions act as natural pest repellents, protecting watermelon vines from predatory animals and insects through their pungent odor. 

Onions don’t create much shade, which is good for watermelon plants. Plus, onion bulbs can be easily pulled once watermelons are harvested.

Onions also have anti-fungal qualities that can protect growing watermelon plants from disease.

abundant growth of onion plants in the garden

4. Beans

Bush or pole beans make excellent companion plants for many plants and vegetables. This is because bean plants increase the amount of nitrogen in the soil, thus giving nearby plants a nutritional boost.

mature green beans in the garden

5. Corn

Sweet corn is a fragile annual crop that grows during the warm season. Its kernels can be yellow, white, or a combination of both colors.

Corn stalks provide support for watermelon vines as they grow. Keep in mind that corn stalks will cast some shade, so take note of where their shadows are cast before planting watermelons nearby since watermelon plants require lots of sunlight.  

6. Tansy

Tansy is known for its frond-like leaves and its brilliant clusters of button-like yellow flowers that grow during the summer.

Tansy is a tenacious companion plant that increases the amount of potassium in the soil, which is ideal for watermelon plants and other plants in the garden. 

This plant is also effective in warding off a wide variety of pests, including mice, ants, flies, fleas, moths, mosquitoes, and ticks. Tansies also attract bees, which help with plant pollination.

yellow button tansy flowers

7. Oregano

Oregano is a blooming herb that emits an aroma that attracts pollinators and repels pests, thus attributing to the growth of healthy neighboring plants, including watermelon.

Alaine Connolly
Alaine has been working way too hard in horticulture since 1992, beautifying golf courses, resorts, and hotels. She is a part time landscape designer who works full time caring for a 28,000 square foot public garden. At home, she maintains her own 400 square feet plot. Alaine lives in northern Illinois - zone 5b.
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