12 Best Companion Plants You Can Grow With Watermelon

As the warm embrace of spring transitions into the balmy days of summer, gardens across Nebraska come alive with the promise of abundant harvests. Among the stars of the season, the watermelon stands tall, its juicy sweetness a hallmark of summertime bliss. In the Cornhusker State, where the fertile soils and ample sunshine create the perfect conditions for bountiful crops, watermelon season spans from May to September, offering ample time for gardeners to revel in its succulent delights.

But what if we told you there's a way to not only cultivate thriving watermelons but also enhance their growth and flavor? Enter the world of companion planting, where strategic alliances between plants unlock a symphony of benefits for the entire garden ecosystem. In this guide, we'll explore 12 companion plants that, when paired with watermelon, can elevate your harvests to new heights. From aromatic herbs to vibrant flowers, these companions not only enrich the soil but also ward off pests and boost the health of your watermelon plants.

So, as the watermelon vines begin to sprawl and the promise of sweet, crisp fruit beckons, join us on a journey through the art of companion planting—a journey that promises not only a fruitful harvest but also a deeper connection to the rhythms of nature

The Magic of Companion Planting

Companion planting is like hosting a garden party where each plant brings its own unique contribution to the table. It's an age-old gardening technique centered on nurturing symbiotic relationships between different plant species, creating a thriving ecosystem right in your backyard. Watermelon companion planting is a gardening technique where specific plants are strategically grown near watermelon vines to enhance growth, deter pests, improve soil quality, and promote overall health. If you need watermelon seeds, I recommend this bundle pack.

Think of it as teamwork for plants – by strategically placing companions together, you can unlock a multitude of benefits for your garden:

• Enhancing growth. Certain plants can complement each other's growth patterns, leading to healthier and more robust crops.
• Warding off pesky pests. Some plants naturally repel common garden pests, acting as natural protectors for their neighbors.
• Boosting soil fertility. Companion plants can work together to improve soil quality, providing essential nutrients for optimal plant growth.
• Structural support.  Tall or vining plants can offer support and shade to others, creating a harmonious and efficient use of space.

When it comes to growing watermelons, choosing the right companions can transform your melon patch from ordinary to extraordinary! Companion planting isn't just about growing watermelons—it's about cultivating an entire ecosystem right in your patch, where every plant plays a crucial role in supporting the health and vitality of the others. 

Companion planting offers numerous benefits for watermelons. It helps control pests like cucumber beetles and spider mites, improves soil quality and nutrient uptake, reduces weed growth, and provides natural pest control through the attraction of beneficial insects. 

I know you are now excited to move forward. So, let's embark on a journey into the world of companion planting tailored specifically for watermelon cultivation, and discover how these plant partnerships can work wonders for your garden.

1. Alyssum

Alyssum, scientifically known as Lobularia maritima, is a petite flowering plant renowned for its role as a ground cover. This botanical gem serves as a natural barrier against soil erosion while enhancing moisture retention and fortifying soil structure. Its intricate root system not only steadies the earth but also fosters an environment conducive to the development of robust root systems in watermelon plants.

Growing Requirements:

• Sunlight Preference: Full sun, 6-8 hours daily.
• Soil Texture: Moist, well-draining.
• Soil pH: Slightly acidic to neutral, 6.0-7.0.
• Temperature: Adaptable, prefers cooler temperatures.
• Relative Humidity: Moderate, avoid excess moisture.
• Optimum Watering Schedule: 1 inch per week, increase in hot/dry weather.
• Harvest Index: Mostly ornamental, minimal harvesting.
• Hardiness Zone: Zones 4-9.
• Propagation: Seeds or cuttings, direct sow or transplant.
• Maintenance: Regular watering, pest control, and pruning.

Exercise caution against excessive fertilization, as it may stimulate disproportionate foliage growth at the expense of flowering. Mitigate humidity-related fungal concerns, particularly in humid environments. For taller varieties, provide adequate support or trellising to prevent sprawling.

2. Basil

With its fragrant leaves, basil serves as a versatile partner for watermelon plants. Not only does it add a pleasant taste to watermelon fruits, but it also acts as a natural insect repellent. The strong aroma of basil deters pests that could harm watermelon plants. This aromatic herb plays dual roles in the garden, enhancing both the flavor of watermelon and protecting it from pests, fostering a favorable environment for watermelon growth.

Growing Requirements

• Sunlight Requirement: 6-8 hours of full sunlight daily. 
• Soil Texture Requirement: Well-draining soil with a light texture. 
• Soil pH: Slightly acidic to neutral, pH 6.0-7.5. 
• Temperature: Flourishes in warm climates, 70°F to 90°F (21°C to 32°C). 
• Relative Humidity: Moderate humidity, 40%-60%. 
• Optimum Watering Schedule: Keep soil consistently moist, watering when top inch feels dry. 
• Harvest Index: Entire plant harvestable, remove flower buds for better leaf production. 
• Hardiness Zone: Zones 9-11, can be grown as annual in cooler climates or indoors. 
• Propagation: Seeds or cuttings, sow seeds after last frost, root cuttings in water or soil. 
• Maintenance: Regular fertilization, remove flower buds, prune for airflow, protect from cold below 42°F (5.5°C). 
• Special Requirements: Mulching for moisture retention, pruning for airflow, protect from cold temperatures.

3. Borage 

Borage's vibrant blue flowers attract pollinators for better fruiting, while its hairy leaves deter pests from harming watermelon plants. Plus, it enriches soil fertility, aiding robust watermelon growth. 

Growing Requirements:

• Sunlight Requirement: Full sun preferred, partial shade tolerated.
• Soil Texture Requirement: Moderately moist, well-drained soil with added organic matter.
• Soil pH: Wide tolerance, prefers slightly acidic conditions.
• Temperature: Hardy, intolerant to hard frosts.
• Relative Humidity: No specific requirements.
• Optimum Watering Schedule: Keep soil evenly moist during establishment, then allow slight drying between waterings.
• Harvest Index: Leaves and flowers harvestable for culinary and medicinal use.
• Hardiness Zone: USDA zones 3-9.
• Propagation: Seeds sown directly or transplanting seedlings.
• Maintenance: Periodic feeding with phosphorus-rich fertilizer, regular watering, pest and disease monitoring.
• Special Requirements: Ensure spacing for growth, deadhead flowers, protect from frost, support tall varieties.

4. Buckwheat 

Buckwheat, a rapid-growing cover crop, effectively stifles weed growth while enhancing soil quality. Through its dense network of roots, it enriches the soil with organic material, fostering favorable conditions for watermelon cultivation. Moreover, buckwheat's unique capacity to scavenge phosphorus and enhance its accessibility to plants bolsters soil fertility, accentuating its benefits for watermelon growth.

Growing Requirements:

• Sunlight Requirement: Thrives in full sun, tolerates partial afternoon shade.
• Soil Texture Requirement: Grows well in any soil type with good drainage.
• Soil pH: Prefers slightly acidic to neutral pH (around 6.0 to 7.0).
• Temperature: Not frost-tolerant, prefers warmer temperatures.
• Relative Humidity: Tolerates a range of humidity levels, prefers moderate humidity.
• Optimum Watering Schedule: Requires regular watering to keep soil moist but not waterlogged.
• Harvest Index: Seeds mature in 8 to 12 weeks, can be harvested for culinary use or cover crop.
• Hardiness Zone: Suitable for USDA hardiness zones 3 to 10.
• Propagation: Sow seeds directly into cultivated soil, spacing 2 inches apart and half an inch deep.
• Maintenance: Low-maintenance, water regularly, occasional fertilization, control weeds.
• Special Requirements: Incorporate balanced organic fertilizer before planting, remove mature plants to limit reseeding.

5. Clover 

Clover serves as a valuable nitrogen-fixing agent, enriching soil fertility by converting atmospheric nitrogen into a usable form for plants. This enrichment elevates the soil's nutrient profile, furnishing vital elements crucial for watermelon development. Additionally, clover's growth pattern aids in soil erosion prevention and fosters the establishment of a robust soil structure, further supporting the growth of watermelon plants.

Growing Requirements:

• Sunlight Requirement: Prefers full sun, tolerates partial shade.
• Soil Texture Requirement: Thrives in well-drained, moist soil.
• Soil pH: Prefers acidic soil.
• Temperature: Hardy in USDA Zones 3-10, tolerates various temperatures.
• Relative Humidity: No specific humidity needs.
• Optimum Watering Schedule: Keep soil moist during establishment, drought-tolerant once established.
• Harvest Index: Primarily used as cover crop or forage, not typically harvested.
• Hardiness Zone: USDA Zones 3-10.
• Propagation: Propagated by seeds, sown on soil surface or lightly raked.
• Maintenance: Regular watering during establishment, periodic mowing or trimming.
• Special Requirements: Lime may be needed for optimal pH, control competing vegetation before planting, mix seeds with lime or fertilizer for easier distribution, avoid strong fertilizers.

6. Comfrey 

Comfrey plays a crucial role in supporting watermelon growth with its unique attributes. Its deep roots delve into the soil, extracting vital nutrients and making them accessible to nearby watermelon plants. This nutrient-sharing quality significantly enhances the development and robustness of watermelons. Moreover, the broad leaves of comfrey provide valuable shade, aiding in moisture retention and fostering an ideal environment for watermelon cultivation.

Growing Requirements: 

• Sunlight Requirement: Prefers full sun to partial shade, especially in hotter climates.
• Soil Texture Requirement: Adaptable to most soil types, thrives in moist, fertile soil rich in organic matter.
• Soil pH: Best in slightly acidic to neutral soil, pH 6.0 to 7.0.
• Temperature: Tolerates wide temperature ranges but prefers moderate conditions.
• Relative Humidity: No specific humidity needs, prefers moderate moisture levels.
• Optimum Watering Schedule: Water when top 2 inches of soil are dry, maintaining moderate soil moisture.
• Harvest Index: Primarily grown for medicinal use, leaves harvested for herbal remedies.
• Hardiness Zone: Hardy in USDA zones 4-9.
• Propagation: Propagate from root cuttings, crown divisions, or transplants, with root cuttings being the most common method.
• Maintenance: Fertilize with nitrogen-rich fertilizer before planting and regularly thereafter. Ensure proper soil moisture and spacing for optimal growth.
• Special Requirements: Plant in a checkerboard arrangement with rows 2-3 feet apart for higher yields. Monitor soil fertility and moisture levels regularly.

7. Dill

Dill is like a good friend for watermelon as it attracts beneficial insects, such as ladybugs and predatory wasps, which contribute to natural pest control in the garden. As it grows, dill adds organic matter to the soil when it decomposes, enhancing soil fertility. Its plant roots also have allelopathic effects, inhibiting the growth of certain weeds.

Growing Requirements:

• Sunlight Requirement: Needs 6-8 hours of full sunlight, can handle some shade.
• Soil Texture Requirement: Likes loose, well-draining soil with lots of organic matter.
• Soil pH: Prefers slightly acidic to neutral soil, but can handle slightly alkaline conditions.
• Temperature: Tough, can handle cold down to 25°F, but loves it around 70°F.
• Relative Humidity: Doesn't care much about humidity levels.
• Optimum Watering Schedule: Keep soil consistently moist, but not soggy.
• Harvest Index: Harvest leaves anytime, seeds when they're fully dry.
• Hardiness Zone: Can grow in USDA zones 3 to 11, depending on the type.
• Propagation: Easy to grow from seeds, and it self-seeds too.
• Maintenance: Water regularly, prune sometimes, watch for pests.
• Special Requirements: Light on the fertilizer, and pick leaves often to keep it growing.

8. Marigold 

Marigolds are great for watermelon because they keep pests away. They create a protective zone around watermelon plants by releasing compounds that nematodes hate, which helps prevent soil-borne diseases. Plus, their colorful flowers attract good bugs that support watermelon growth.

Growing Requirements:

• Sunlight Requirement: Needs 6-8 hours of direct sunlight daily.
• Soil Texture Requirement: Likes well-draining soil, pH 6.0 to 7.0.
• Temperature: Loves heat, zones 2 to 11.
• Watering: Water regularly at first, then weekly.
• Maintenance: Remove spent flowers, don't over-fertilize.
• Special Requirements: Plant in full sun, good drainage, watch for powdery mildew.

9. Mustard

Mustard plants bring biofumigation benefits to the table, releasing compounds that suppress soil-borne pathogens and pests, thereby reducing the risk of diseases impacting watermelon plants. Moreover, as they decompose, mustard plants enrich the soil by incorporating organic matter, enhancing its fertility and nutrient content.

Growing Requirements:

• Sunlight Requirement: Full sun for optimal growth, partial shade for baby greens.
• Soil Texture Requirement: Prefers fertile, moist, well-draining soil.
• Soil pH: Thrives in slightly acidic soil below pH 6.0.
• Temperature: Cool-season crop, tolerates down to 32°F, dislikes temps over 75°F.
• Relative Humidity: Moderate humidity preferred, maintain soil moisture.
• Optimum Watering Schedule: Keep soil consistently moist, aim for 1 inch of water weekly.
• Harvest Index: Harvest greens before bolting, seeds when mature and dry.
• Hardiness Zone: Grows in various zones with cool to moderate climates.
• Propagation: Propagated from seeds, sow directly or start indoors.
• Maintenance: Monitor soil moisture, control pests, provide support in hot weather.
• Special Requirements: Use high-nitrogen fertilizer, protect baby greens from strong sunlight.

10. Nasturtium

Nasturtiums, Tropaeolum majus, with their vivid blossoms and circular foliage, serve as fantastic partners for watermelon cultivation. Their cascading vines offer effective ground coverage, minimizing weed growth and preserving soil moisture levels. Moreover, nasturtiums act as natural insect repellents, discouraging pests that could threaten watermelon plants. Additionally, they play a crucial role in attracting pollinators, leading to improved fruit development and overall plant robustness.

Growing Requirements:

• Sunlight Requirement: full sun (6+ hours)
• Soil Texture Requirement: Prefers well-draining, light-textured soil to encourage flower production over foliage.
• Soil pH: Best in slightly acidic to neutral soil, pH 6 to 8.
• Temperature: Likes daytime temps in the 70s F, can handle light frost, but not freezing.
• Relative Humidity: Adapts to average humidity, struggles in extreme dryness or humidity.
• Optimum Watering Schedule: Moderate watering, about once a week, more in hot or dry conditions.
• Harvest Index: Primarily ornamental, leaves and flowers edible for culinary use.
• Hardiness Zone: Hardy in USDA zones 10-11, grown as annuals elsewhere.
• Propagation: Propagated from seeds, preferably sown directly due to sensitive roots.
• Maintenance: Avoid synthetic fertilizers, regular watering, occasional pruning for shape and removing spent blooms.
• Special Requirements: Protect from late frost, balanced moisture preferred, mulching helps conserve moisture, avoid over-fertilizing.

11. Oregano 

Oregano (Origanum vulgare), a beloved culinary herb, plays a vital role in the growth of watermelon by offering natural pest protection. Rich in aromatic oils, oregano serves as a natural insect repellent, warding off pests that could harm the watermelon crop. Additionally, its low-growing habit acts as effective ground cover, minimizing soil erosion and preserving essential moisture levels. By creating a pest-resistant and well-protected environment, oregano contributes significantly to the overall health and productivity of watermelon plants.

Growing Requirements: 

• Sunlight Requirement: Prefers sunny spots but needs partial shade in hotter climates (Zone 7 and below) during the afternoon.
• Soil Texture Requirement: Flourishes in well-drained soil, pH 6.5 to 7.0. Add compost for better root growth.
• Soil pH: Likes slightly acidic to neutral soil, pH 6.5 to 7.0.
• Temperature: Thrives in Zone 7 and warmer. Protect in colder zones in winter or grow indoors.
• Relative Humidity: Adapts well to various humidity levels, prefers moderate levels.
• Optimum Watering Schedule: Keep soil consistently moist, but don't overwater. Prefers slightly drier conditions.
• Harvest Index: Harvest sprigs with sharp shears, prune up to one-third of the plant for new growth.
• Hardiness Zone: Hardy in Zone 7 and southward. Protect in colder zones with mulch or bring indoors in winter.
• Propagation: Propagate from cuttings or seeds, best in spring or fall.
• Maintenance: Feed regularly with water-soluble plant food, trim back in late spring for bushier growth.
• Special Requirements: Use premium potting mix for containers, consider indoor hydroponic systems for year-round growth.

12. Peas 

Peas, scientifically known as Pisum sativum, are vibrant annuals within the legume family. Characterized by their delicate tendrils, compound leaves, and succulent pods bearing tender peas, these versatile plants bring both beauty and bounty to the garden. As excellent nitrogen fixers, peas enrich the soil by converting atmospheric nitrogen into a form that other plants can readily use, making them valuable companion plants that enhance soil fertility and support the growth of neighboring crops.

Growing Requirements:

• Sunlight Requirement: Needs full sun for at least 6 hours daily, better yields in full sun.
• Soil Texture Requirement: Loves well-draining, organic-rich loamy soil for healthy roots.
• Soil pH: Prefers slightly acidic to neutral soil, pH 6.0 to 7.0.
• Temperature: Thrives in mild temps of 60-70°F, struggles above 85°F.
• Relative Humidity: Soil moisture is key, prefers consistent levels without waterlogging.
• Optimum Watering Schedule: Keep soil consistently moist, aim for 1 inch of water weekly.
• Harvest Index: Snap peas when plump but tender, shelling peas when pods are filled, snow peas when flat with small peas.
• Hardiness Zone: Grows well in USDA zones 3-10, varies by variety.
• Propagation: Plant seeds directly, 1 inch deep, 2 inches apart in rows 7 inches apart.
• Maintenance: Regular watering, support vining types, pest and disease control, mulching for moisture and weed suppression.
• Special Requirements: Support vining varieties with stakes or trellises, avoid heavy nitrogen fertilization, harvest promptly for continuous production.

FAQs (Companion Plants You Can Grow With Watermelon

Conclusion

Companion planting can be especially beneficial in a homestead garden setting, where maximizing space, promoting natural pest control, and enhancing soil fertility are often top priorities for sustainable gardening practices. Some other good reasons to try watermelon companion planting include promoting biodiversity in the garden, reducing reliance on chemical pesticides and fertilizers, maximizing garden space, and fostering a healthier and more sustainable gardening ecosystem.