Are you considering growing your food and planting watermelon this season? You may want to consider adding a few watermelon companion plants to your patch if you are.
There are companions for watermelon that will help repel pests, attract pollinators (which you need with your watermelons!) and a few that help improve the soil.
Garlic, onions, chives, nasturtiums, marigolds, lavender, aromatic herbs (like dill, mint, catnip, and lavender), hairy vetch, radish, corn, beans, and peas of all kinds all make great companions for watermelons.
The best Companion Plants for Watermelon
There are many wonderful companions you can plant alongside your watermelons:
Garlic, Onions, and Chives
Allium family members such as garlic, onions, and chives, are some of the best companion plants for watermelons. Their pungent aroma repels and confuses many pesky harmful insects like flea beetles, many aphid species, whiteflies, and black flies.
Garlic emits sulfur into the soil, which will have antibacterial and anti-fungal properties. It can help prevent diseases.
- Learn More: Garlic is one of the best companion plants to add to your home garden. We have the complete guide on the best use of garlic at planting time.
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Nasturtiums and Marigolds
Marigolds and lavender are strongly scented flowers that will help drive away pests like cucumber beetles which will spread disease through your garden space.
Plant nasturtiums around your watermelons as a trap crop for aphids and beetles.
These flowering plants will also attract pollinators to your watermelon blossoms.
- Learn More: Flowers make an excellent addition to the garden, especially when used as companion plants. We have extensive guides for both nasturtiums and marigolds that can help plan out your garden beds this season.
- Related: We also have a complete growing guide for nasturtiums!
Dill, Mint, Catnip and Lavender
Herbs are always a good choice as watermelon companions.
Herbs will help drive away harmful pests with their heavy pungent aromas.
Learn More: We have growing guides for so many aromatic herbs. If you’re feeling challenged by growing herbs in your garden, don’t be! Check our guides for growing these watermelon companion herbs:
- How to Grow Dill
- Growing Catnip (so much fun if you have cats!)
- Growing Lavender in pots
- See the complete list of lavender companion plants
- and Growing mint, including an article on the best mint companion plants.
Hairy vetch is one of the best companions for watermelon.
Plant a cover crop of hairy vetch where you want to grow your watermelon. Cut back the vetch just before it blooms and leave the cuttings on the garden bed as mulch.
Vetch has many benefits, including controlling Fusarium wilt, anthracnose, and gummy stem blight, which can affect your watermelons.
Some studies suggest that growing watermelon after a cover crop of hairy vetch can increase the sugar content of the fruits.
You can use radishes around the edges of your growing hills to act as a trap crop for harmful insects like beetles. For example, cucumber beetles will transmit wilt to your watermelon plants if left untreated.
Radishes also help break up the soil.
Corn and watermelon do not share diseases or pests, making them good companions.
Although watermelons require full sun for best production, there is a healthy balance in the hot midday sun. Watermelon leaves can burn, and planted near corn can provide shade, but be sure to plant corn where it will not fully shade your watermelon.
- Learn More: See all the wonderful companion plants you can add to your corn patch.
Bush Beans, Peas, and Pole Beans
Bush beans and pole beans fix nitrogen in the soil, making it available to the watermelon.
Peas and pole beans can also be grown as a ground cover with the watermelon vines, which will help shade out weeds and keep the soil moist.
- Related Post: Did you know you can grow peas and bush beans in containers? You can, and you can harvest lots and lots of fresh produce all summer long.
Poor companions for watermelon
There are several plants you will not want to grow alongside your watermelon. These plants will cause overcrowding, poor circulation, and competition for nutrients, water, and sunlight!
Cucumbers and Zucchini
Cucumbers and zucchini share the same pests and diseases as watermelon and should not be grown together.
In addition, cucumber, zucchini, and watermelon share similar soil nutrients and moisture requirements, creating a competitive environment where all plants suffer.
- Learn More: Cucumbers and zucchini have many wonderful companions. Check out our complete guides for companion plants for cucumbers and companion plants for zucchini.
Squash and Pumpkins
Squash and pumpkins will also compete for nutrients and water and share the same diseases as watermelon, making them poor companion plants for watermelon.
In addition to these challenges, pumpkins and squash grow large and can take over a space very quickly. Your pumpkin vines can very easily overtake your watermelons.
- Learn more: Although pumpkins make poor watermelon companions, there are several great companions to plant along with your pumpkin vines.
Tomatoes make very poor companion plants for watermelon.
Large vining crops like tomatoes will grow tall and can shade out the watermelons too much, causing stunted growth in the watermelons.
Potatoes also make poor companion plants for watermelon.
Aphids are attracted to potatoes. Unfortunately, many aphid species will attack the vines of the watermelon, so it’s best to keep these two plants growing away from one another.
- Learn More: See the full guide for companion planting with potatoes.
Sunflowers attract aphids in droves. They also provide far too much shade for melons to grow well. It’s best to plant these beautiful flowers in another food garden area.
Related: Learn how to grow sunflowers! Although sunflowers make poor companions for watermelons, they are a must-have in the garden.
The Many Benefits of Companion Planting
Companion planting offers many benefits for the home gardener. Using companion planting in your garden can help:
Attract beneficial pollinators: Planting flowers around the garden will help encourage pollinators to visit your plants.
Attract beneficial insects: Flowers and herbs will also attract beneficial insects such as wasps, ladybugs, hoverflies, ground beetles, spiders, and lacewings.
Deter Pests: Plants like chives, garlic, and onions will repel common insect pests, such as aphids, beetles, flea beetles, and mites.
Companion plants can help with weed control. For example, densely planted greens like spinach or low-growing flowers like nasturtiums can act as a mulch to choke out and help prevent weeds.
Will help with disease problems in your garden: Diseases are spread quickly through gardens when plants of the same type are grouped in extensive mass plantings.
- Learn More: Companion Plants for the In The Veggie patch
Tips for growing healthy, robust watermelon
Here are a few garden tips for growing watermelons:
How to Plant Watermelons
You can directly sow seeds in the garden, but it pays to get ahead by planting seeds indoors four weeks before planting out or purchasing starts from a garden nursery.
Wait until the ground temperature reaches 70F before you plant watermelon out, or three weeks after your last average spring frost—plant watermelon in full sun in rich, well-draining soil for best results.
Spacing watermelon in the garden
Spacing is vital to ensure plants do not overgrow into one another. In addition, air circulation is key to helping prevent and spread disease through the garden, so resist planting watermelons closer together than required.
Plant 3-5 seeds together on a hill 1 inch apart. Space hills 3 feet apart. The watermelon will grow and cover the ground all around the hills quickly.
Consider using a support system like a trellis to keep your watermelons off the ground.
- Learn More: See our guide on vertical gardens and using support systems to free up precious gardening space and clean your vining fruit.
Fertilizing Watermelons for Best Yields
Watermelon plants are heavy feeders. Add lots of compost and organic matter to the hills before planting. Watermelons benefit from green sand and bone meal and help to increase fruit production.
Cucumber Beetles and Aphids – The Insect Pests You Want to Avoid
Cucumber beetles and aphids will be your primary nemesis while growing watermelons. Plant many pest-deterring flowers and herbs around your patch to help prevent them, but be ready with other methods for controlling pests by having or making insecticidal soaps.
Troubleshooting For Watermelon Problems
Here are a few common challenges growing watermelons and their causes:
Why are my watermelons flavorless?
Very cool summers and or overwatering will cause melons to be relatively flavorless. Try mulching with black plastic or growing your watermelon in a high tunnel to help retain moisture and provide more heat.
Why are my watermelon vines wilting?
If your vines suddenly wilt, it could be caused by bacterial wilt. Some beetles cause bacterial wilt, and there is no cure. You must pull and destroy your vines (do not compost!).
How do I know when to Harvest my watermelon plants?
Check the tendril at the base of the stem where the fruit attaches to the vine. The watermelon is ready for harvest when the tendril is brown and dried.
Are you interested in companion planting and looking for more resource information?
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We have three companion planting books that we highly recommend having on hand as a resource:
And a few helpful posts to help you grow great vegetables: