🍉 Royal Sweet Watermelon

What it looks like

Why this variety

Royal Sweet is a mid- to late-season Allsweet-type watermelon: blocky-oval fruit, light-green rind with darker stripes, bright red flesh, typically 20 to 25 pounds. Allsweet types are the backbone of Southern watermelon growing — firm, sweet, good-keeping fruit with the broken-stripe rind pattern that makes them easy to spot in a patch.

For Florida growers, Royal Sweet is a steady, proven choice rather than a novelty: a full-season vine that wants warm soil, full sun, and room, and pays back with uniform, market-quality melons. It sits comfortably alongside Allsweet and Sangria in the same family, so if you have grown either of those, you already know how to grow this one — the difference is in the details of rind and shape, not in the care.

How to grow

Direct sow after the soil hits 70°F or warmer — watermelons germinate in heat or not at all. Plant about 1 inch deep in hills (3 to 4 seeds per hill, thin to the 2 strongest plants), or start indoors 3 to 4 weeks early in peat pots, because watermelons hate root disturbance. Black plastic mulch warms the soil, suppresses weeds, and keeps the fruit clean in Florida’s sandy beds.

Watermelons are space-hungry: plan for vines 10 feet or more, and do not crowd them, because crowded vines stay wet, and wet vines get disease. Row cover until flowering keeps cucumber beetles off young plants — they vector bacterial wilt, which has no cure — then remove it so bees can reach the flowers. Rotate beds: never follow melons, cucumbers, or squash with melons, because fusarium wilt builds up in warm soil and waits for the next crop.

Water & feeding

Deep, regular water during vine growth and fruit set — then TAPER OFF as fruit approaches ripeness. This is the single biggest flavor lever you have: a melon watered heavily right up to harvest tastes watery, while one tapered at the end concentrates its sugars. Mulch holds the even moisture that prevents cracking and blossom-end problems in Florida’s cycle of downpour and drought.

Feed at planting with worm castings worked into the hill, and side-dress at flowering. Too much nitrogen late in the season means lush vines and bland fruit — the plant version of studying for the wrong exam. A little potassium as fruit sizes helps sugars and rind quality.

Common problems

• Cucumber beetles: row cover until flowering; they vector bacterial wilt, which has no cure — prevention beats cure.
• Fusarium wilt: a soil fungus that yellows and collapses vines, worst in warm soil. Rotate beds for years, not months, and prefer resistant varieties where they exist.
• Anthracnose and gummy stem blight: leaf and fruit spots that love warm, wet weather. Airflow, mulch, base watering, and resistant varieties are the defense; remove badly spotted leaves rather than letting them rain spores onto fruit.
• Melonworm and pickleworm: Florida caterpillars that chew leaves and bore into fruit. Hand-pick, watch for frass, and use Bt early on young caterpillars.
• Poor fruit set: usually a lack of pollinators. Hand-pollinate with a paintbrush if bees are scarce — female flowers carry a tiny melon at the base.

Harvest

Ripe when the ground spot is creamy yellow, the nearest tendril is dry, and the thump sounds hollow. Harvest by the trio of signs, not by the calendar alone: a creamy-yellow ground spot where the melon sat, a dried tendril nearest the fruit, and a deep, hollow thump. One sign alone lies; all three together rarely do. Cut the stem, lift — do not drag — and chill the melon before cutting for the crispest flesh.

Saving seeds

Royal Sweet is a mid- to late-season Allsweet-type watermelon: blocky-oval fruit, light-green rind with darker stripes, bright red flesh, typically 20 to 25 pounds. Allsweet types are the backbone of Southern watermelon growing — firm, sweet, good-keeping fruit with the broken-stripe rind pattern that makes them easy to spot in a patch. As an open-pollinated watermelon it comes true from seed: direct sow after the soil hits 70°F or warmer — watermelons germinate in heat or not at all. Plant about 1 inch deep in hills (3 to 4 seeds per hill, thin to the 2 strongest plants), or start indoors 3 to 4 weeks early in peat pots, because watermelons hate root disturbance. Black plastic mulch warms the soil, suppresses weeds, and keeps the fruit clean in Florida’s sandy beds. The full method is in the Saving seeds section of the Watermelon guide.