Growing Watermelon (Citrullus) in Your Garden: What You Need to Know
If you’ve ever dreamed of growing your own juicy watermelons, you’re thinking about Citrullus – the genus that gives us those perfect summer treats! While watermelons aren’t native to North America, they’ve found their way into gardens across the continent and can be a fun (if space-hungry) addition to the right landscape.
What Exactly Is Citrullus?
Citrullus is a genus of annual plants that belong to the gourd family. These sprawling herbs lack woody tissue and grow as trailing vines with deeply lobed leaves and bright yellow flowers. Originally hailing from Africa, watermelons have become naturalized across much of the United States, from Alabama to Wisconsin and everywhere in between.
Where You’ll Find Them Growing Wild
As a non-native species, Citrullus has established itself in the wild across an impressive range of states and territories. You might spot these escaped garden plants growing spontaneously in Alabama, Arizona, Arkansas, California, Connecticut, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, West Virginia, Wisconsin, as well as in Palau, Puerto Rico, Virgin Islands, and Navassa Island.
Should You Grow Watermelon in Your Garden?
The decision to grow Citrullus comes down to space, climate, and your gardening goals. Here’s what to consider:
The Pros:
- Delicious, homegrown fruit that’s hard to beat on a hot summer day
- Attractive yellow flowers that provide some pollinator benefits
- Can serve as an interesting ground cover in large spaces
- Fun project for gardeners who enjoy a challenge
The Considerations:
- Requires significant space – these vines can sprawl 6-20 feet in all directions
- Needs a long, warm growing season to produce fruit
- Provides limited wildlife benefits (only 2-5% of diet for small mammals and birds)
- As a non-native species, doesn’t support local ecosystems like native plants would
Native Alternatives to Consider
If you’re interested in supporting local wildlife and ecosystems, consider these native alternatives that offer similar trailing growth habits or edible benefits:
- Wild strawberry (Fragaria species) for ground cover with edible fruit
- Native grapes (Vitis species) for climbing vines with wildlife benefits
- Ground cherry or husk cherry (Physalis species) for unusual edible fruits
How to Grow Watermelon Successfully
If you decide to grow Citrullus, here’s how to set yourself up for success:
Growing Conditions:
- Sunlight: Full sun (6-8 hours daily minimum)
- Soil: Well-draining, fertile soil with good organic content
- Space: Allow 6-12 feet between plants in all directions
- Climate: Needs consistent warmth – soil temperature should be at least 70°F
USDA Hardiness Zones:
Watermelons can be grown as annuals in zones 3-11, but they perform best in zones 5-11 where the growing season is long enough for fruit development.
Planting and Care Tips:
- Start seeds indoors 2-4 weeks before the last frost, or direct sow after soil has warmed
- Plant seeds 1 inch deep in hills or rows
- Water consistently but avoid getting leaves wet to prevent disease
- Mulch around plants to retain moisture and suppress weeds
- Consider using row covers early in the season to maintain warmth
- Hand-pollinate flowers if you notice poor fruit set
- Support developing fruits with boards or cloth to prevent rot
The Bottom Line
While Citrullus watermelons can be a rewarding crop for gardeners with ample space and patience, remember that they’re not contributing to local ecosystems the way native plants would. If you choose to grow them, enjoy the process and the sweet rewards – but also consider dedicating some garden space to native plants that will support local wildlife and pollinators year after year.
Whether you’re team watermelon or team native plants (or better yet, team both!), the most important thing is getting out there and growing something that brings you joy.
