Watermelon is a classic summer crop, but its sprawling vines, which can cover six to twelve feet in traditional planting, pose a challenge in a raised bed. While raised beds offer superior soil control and drainage, their confined borders require gardeners to rethink conventional spacing. The solution is applying intensive planting strategies and maximizing vertical space to achieve a successful harvest in a small footprint.
Understanding Intensive Spacing
Traditional spacing (four to six feet between vining watermelons) is impractical for the average four-foot-wide raised bed. Gardeners should adopt intensive planting, leveraging the controlled, nutrient-rich environment to support closer plants. This tighter arrangement is only viable when paired with vertical growing methods.
For naturally compact bush varieties, two to three feet between plants is sufficient. Vining varieties grown vertically can be planted 12 to 18 inches apart at the base of a trellis. This reduced horizontal space works because the raised bed’s deep, well-draining soil provides the root system with ample nutrients and moisture. The trade-off for this efficiency is the increased need for consistent watering and regular feeding, as the plants quickly deplete available resources.
Selecting the Right Watermelon Varieties
Intensive spacing requires choosing a watermelon variety whose growth habit matches the available space. Watermelons fall into two categories: vining and bush/dwarf. Vining types, such as ‘Charleston Gray’ or ‘Crimson Sweet,’ produce long runners that can spread over ten feet and require a sturdy support system.
Bush or dwarf varieties are bred for compact growth, with vines typically reaching only three to five feet. These are the ideal choice for small raised beds because they conserve horizontal space. Examples include ‘Bush Sugar Baby,’ ‘Bush Jubilee,’ and ‘Bush Charleston Gray’. Selecting a bush variety maximizes yields, even though the individual fruits tend to be smaller, ranging from icebox size to around 15 pounds.
Utilizing Vertical Growth Techniques
Growing watermelons vertically is the primary method for making intensive spacing successful in a raised bed. This requires installing a strong support structure before planting, such as a sturdy wire mesh, an A-frame, or a cattle panel secured to the frame. Since watermelon vines do not climb, the gardener must gently guide and secure the main vines to the trellis using soft plant ties or garden twine. This training ensures the foliage receives optimal air circulation and sunlight, reducing the risk of disease.
A crucial step in vertical growing is providing physical support for the developing fruit. Watermelons grow heavy, and the vine stem cannot bear the full weight of a maturing melon. Once the fruit reaches the size of a tennis ball or larger, it must be supported with a sling or hammock attached to the trellis. Slings can be fashioned from materials like old pantyhose, mesh bags, or strips of soft fabric, ensuring the melon is cradled and the weight is transferred directly to the support structure.