What other homegrown “fruit-vegetable” kindles as much love and laughter as a good old-fashioned watermelon? Picture friends and family at a farmhouse kitchen table or in the back yard, picnicking in the shade of a catalpa tree. Everyone is sated from Sunday dinner. There’s a pause in activity and a somnolent lull. But soon enough it’s time for dessert: an heirloom watermelon, harvested fully ripe and allowed to cool overnight in a tub of water. When thumped, it makes a dull punk sound. When cleft with a knife, it snaps and rumbles, cracking open to reveal an expanse of crisp and juicy red flesh with glistening black seeds. Everyone grabs a slice and dives in. Kids make mischief and spit seeds. This same scenario is impossible to imagine with a seedless—and to my mind soulless—watermelon.
Watermelons originated in Africa, but over the centuries they’ve become part of the American vernacular, ingrained in our culture and traditions. Heirloom watermelons have long been valued by farmers and gardeners, who saved seed year after year for replanting. Humans and watermelons have become “evolutionarily linked.” They exist to feed the people who treasure them. I’m a fan of traditional seeded watermelons of all sizes, shapes, and rind patterns. The giant ones have a special place in my heart.
Heirloom (seeded and open-pollinated) varieties are still grown and relished, but the number is dwindling. Seedless sorts dominate the marketplace. Many consumers prefer small seedless watermelons because they’re “easy,” not realizing that if seeded varieties disappear, something precious will be irretrievably lost.
Mark Twain praised southern-grown watermelons as “a boon apart,” king of all fruits, fit for angels. That the flavor of watermelons grown in the South is unsurpassed is true. Watermelons thrive and reach their fullest expression in long-season areas with hot, dry, sunny weather. With days in the 80s and nights in the 60s, plants yield luscious fruit in as little as 3 months. But you don’t need a southern ZIP code to grow tasty watermelons. There are ways to stretch the season with row covers, hot caps, and plastic mulch.
The best place for growing watermelons is a site in full sun—with a windbreak, so trailing vines don’t flap in the breeze. If you have deep and well-drained soil, such as sandy loam, consider yourself lucky. Watermelons fare poorly in waterlogged and compacted soils. Adding soil amendments and organic matter helps and can provide essential plant nutrients. Aim for an acidic soil, with a pH between 6.0 and 6.5.