Watermelon Companion Plants: What to Grow and What to Avoid

Watermelons are heat-loving, sprawling vines, and the plants you set beside them can decide how well they grow. The best watermelon companion plants pull in the bees your melons need for pollination, lure pests away from the fruit, feed the soil, and make smart use of the space around those wandering vines. Here is exactly what to plant with watermelon, what to keep away from it, and how to lay it all out.

The best companion plants for watermelon

These are the companions that earn their place in a watermelon patch. Each one solves a specific problem, whether that is pollination, pests, soil, or space.

1. Corn

Tall corn gives watermelon vertical structure and a little light afternoon shade during the hottest part of summer, which can ease heat stress on the vines and fruit. In return, the sprawling melon vines shade the soil around the corn and help suppress weeds. It is a classic pairing in the spirit of the Three Sisters, and corn is planted to the north side so it never shades the sun-hungry melons.

2. Bush and pole beans

Beans are nitrogen fixers, working with soil bacteria to pull nitrogen from the air and leave the soil richer for their neighbors. Watermelons are hungry feeders, so that steady supply of nitrogen supports strong vine and leaf growth. Beans also take up little room and are easy to tuck in around the hills.

3. Radishes

Radishes are one of the smartest interplanting choices for watermelon. They sprout and mature fast, so you can sow them right at the melon hills and harvest them long before the vines take over that space. They also help lure cucumber beetles away from your melons, so a quick crop of radishes does double duty early in the season.

4. Nasturtiums

Nasturtiums work as a trap crop, drawing aphids and cucumber beetles to themselves and away from your watermelon leaves and fruit. Their bright, open flowers also attract bees and other pollinators, which watermelon relies on to set fruit. As a bonus, the leaves and blooms are edible and trail nicely as a living ground cover.

5. Marigolds

Marigolds are a garden workhorse for pest control. Their roots help deter root-knot nematodes in the soil, and their strong scent confuses many pest insects while the bright blooms attract beneficial ones like ladybugs and hoverflies. Plant them around the edges of the melon patch for easy, colorful protection.

6. Borage

Borage may be the single best flower to plant with watermelon. Its true-blue, star-shaped blooms are a magnet for bees, and heavy bee traffic is exactly what watermelon needs to pollinate well and set full, evenly shaped fruit. Borage is also believed to deter some pests and improve fruit set on its neighbors, which makes it a natural fit at the edge of the patch.

7. Dill, oregano, and sunflowers

Flowering herbs like dill and oregano, along with sunflowers, bring in pollinators and the beneficial insects that keep pest numbers down. Let a few plants flower rather than cutting them all, and you create a steady draw for bees and predatory insects. Just site sunflowers where their height will not shade the melon vines, keeping them to the north edge.

What not to plant near watermelon

A few neighbors do more harm than good. These are the ones to keep out of the watermelon patch.

Potatoes

Potatoes are heavy feeders that compete hard with watermelon for water and nutrients, and both can be susceptible to overlapping soil-borne diseases. Growing them side by side stresses your melons and raises disease pressure, so keep the two well separated in the garden.

Fennel

Fennel is famously a poor companion for almost everything. It is allelopathic, releasing compounds that can slow or inhibit the growth of most nearby vegetables, watermelon included. If you grow fennel, give it its own corner well away from the melon patch.

Other cucurbits (a nuanced note)

Cucumbers, squash, and zucchini are cousins of watermelon in the cucurbit family, and they can share the same pests and diseases, including cucumber beetles and powdery mildew. You can grow them in the same garden, but do not crowd them together. Give each plant room, keep airflow open, and scout for pests early so a problem in one crop does not sweep through all of them.

Why companion planting works for watermelon

Companion planting is not folklore alone. With watermelon, it lines up with a few very practical needs of the crop.

• Pollination. Watermelon has separate male and female flowers, and bees must carry pollen between them for fruit to form. Flowers like borage, nasturtiums, and marigolds pull in more bees, which means better fruit set and fewer small or misshapen melons.
• Pest control. Trap crops like nasturtiums draw pests away, marigolds help deter nematodes, and flowering herbs invite the beneficial insects that prey on aphids and beetles.
• Living mulch and ground cover. Low, trailing companions shade the soil, hold in moisture, and crowd out weeds around the base of the vines.
• Efficient use of space. Quick crops like radishes and beans fill the gaps early in the season, before the melon vines sprawl out and claim the ground.

How to lay out a watermelon companion garden

A little planning makes companion planting easy. Watermelon vines sprawl, so start with generous spacing and build the companions around them.

• Give the melons room. Plant watermelon in hills and allow roughly 3 to 5 feet between hills so the vines have space to run. Skip crowding them against other big cucurbits.
• Sow quick crops at the hills. Tuck fast radishes and low bush beans right around the melon hills early in the season. You will harvest or turn them under before the vines need that space.
• Ring the edges with flowers. Plant marigolds, nasturtiums, and borage around the border of the patch to draw pollinators in and steer pests away from the fruit.
• Keep tall plants to the north. Set corn and sunflowers along the north edge so they never cast shade over the sun-loving melon vines, and let the melons sprawl toward the sun.

Get the neighbors right and your watermelon patch will be better pollinated, better protected, and more productive, with sweeter melons for your trouble. Below you will find the exact non-GMO, heirloom seeds we grow alongside our own watermelons.