Growing Watermelon: Planting, Care, and Harvest for Sweet Summer Fruit

Everyone loves juicy watermelon in summer. Native to Africa, melons need warmth (80°F days) and a long season. Cooler climates succeed by starting seeds indoors and choosing short-season varieties. Maturity: 70–90 days.

Planting

• Warmer areas: direct sow when soil ≥70°F for good germination.
• Vines tender—transplant only after all frost danger passes (wait 2+ weeks post-last-frost).
• Cooler zones: start indoors ~1 month before transplanting.
• Amend soil with aged manure, seaweed, compost. Watermelons are heavy feeders.
• Preferred pH: 6–6.8.
• Grow in raised rows (hills) for drainage and heat retention. Space 2 ft apart in 5-ft-wide hills.
• Rows: 6 ft × 6 ft spacing.
• Loamy, well-drained soil. Handle transplants gently.
• Post-transplant: row covers for pests. Remove when male and female flowers appear.
• More watermelon planting tips.

Care

• Black plastic mulch: warms soil, suppresses weeds, keeps fruit clean.
• Water critical from planting to fruit set. During growth/bloom/fruit set: 1–2 inches/week.
• Soil moist, not waterlogged. Water vine base morning; avoid wetting leaves/overhead. Reduce watering once fruit grows—dry weather = sweeter melon.
• If fertilizing: more nitrogen than phosphorus/potassium early. After flowering: less nitrogen. Liquid seaweed preferred.
• Pruning optional but may improve productivity: remove lateral (side) vines, stick to main vine. Young: cut end buds before side shoots become vines. Pinch some blossoms to focus energy on fewer melons (hard to sacrifice potential fruit!).
• Male/female flowers separate on same plant. Males appear weeks before females. Don't worry if males drop. Females (swollen bulb at base) stay and fruit.
• Pollination needed—be kind to bees!
• Ripening: gently lift fruit, place cardboard/straw underneath to prevent rot.

Pests and Diseases

• Aphids
• Cucumber Beetles
• Squash Vine Borer Moths
• Fusarium Wilt

Harvest and Storage

Watermelons don't sweeten off vine—harvest timing crucial. Ripen over ~2 weeks; watch closely.

Dr. Bill Rhodes, Clemson horticulture professor, advises how to tell ripeness:

• Thump: hollow sound = ripe.
• Top color: little contrast between stripes = ripe.
• Bottom color: white = unripe; cream/yellow = ripe.
• Press: gives slightly = ripe (Rhodes dislikes this—can ruin quality).
• Tendril: green = wait; half-dead = nearly ripe/ripe; fully dead = ripe/overripe—pick now!
• Cut stems with sharp knife near fruit.
• Uncut: ~10 days. Cut: ~4 days refrigerated, tightly wrapped.

Recommended Varieties

• 'Sugar Baby' – 80 days, 10-lb, bright red flesh. Small fruit: plant 4 ft apart.
• 'Sweet Beauty' – 80 days, 2004 All-America Selection. 6-lb oblong, red flesh.
• 'Golden Midget' – 70 days, petite 3-lb yellow-skinned, pink flesh. Good for North.

Wit & Wisdom

Watermelon is 90% water.

The pumpkin vine never bears watermelons.

August 3 = National Watermelon Day (US)!

Recipes

• Watermelon Basket With Honey Lime Dressing
• Watermelon Cucumber Salad
• Watermelon Punch