🍉 Watermelon
Citrullus lanatus
vegetables
fruit (culinary, cucurbit)
☀️ Sun
Full sun (8+ hours) ABSOLUTELY CRITICAL; watermelons need maximum heat and sunlight , anything less produces bland, small fruit
💧 Water
Medium, high; 1, 2 inches per week during vine growth and fruit development; CRITICAL: reduce watering significantly (or stop entirely if soil has residual moisture) during final 1, 2 weeks of ripening , this dramatically concentrates sugar content; too much water at ripening = watery, bland watermelon
🗺️ Zones
3, 4, 5, 6, 7, 8, 9, 10, 11
🧪 Soil pH
6.0, 7.0 (slightly acidic to neutral); tolerates slightly acidic to 5.5
🪴 Soil Type
Rich, well-drained, sandy loam with generous organic matter; watermelons are heavy feeders , incorporate compost and well-rotted manure; soil MUST be warm (70°F+) before planting; sandy soils warm faster , ideal for watermelons in cooler zones
🚿 Drainage
Excellent drainage ESSENTIAL , watermelons are deep-rooted but hate wet feet; raised beds or hills/mounds critical in heavy soil; black plastic mulch warms soil and suppresses weeds
📏 Spacing
Hills: 2, 3 plants per hill, hills 6, 8 feet apart (watermelons sprawl 10+ feet!); rows: plants 24, 36 inches apart, rows 6, 8 feet; bush/short-vine varieties ('Sugar Baby'): 3, 4 feet spacing; icebox varieties need less space
⏱️ Maturity
75-100 days (from seed/transplant); icebox varieties 75-85 days, large 85-100 days
🍴 Edible Parts
🍽️ Flesh (red, pink, yellow, or orange , the main edible portion; seedless varieties available)
🍽️ Seeds (roasted and salted , popular snack; especially black-seeded varieties; rich in protein and minerals)
🍽️ Rind (pickled , Southern US tradition; also used in stir-fries in some Asian cuisines)
🍽️ Young leaves (edible cooked in some African cuisines , use like spinach)
Key:🤝 Grows well together❌ Keep apart☀️ Sun needs💧 Water🗺️ Hardiness zone
🤝 Companions (8)
Attracts pollinators and beneficial insects; quick summer cover crop that can be turned under before watermelons fully spread; improves soil phosphorus availability
Beans fix nitrogen for heavy-feeding watermelons; beans harvested early, before vines spread; complementary root depths
🤝 Corn (limited)
Traditional intercropping in some regions; corn provides windbreak; watermelons provide living mulch; but both are heavy feeders , adequate spacing and fertility needed
Repels nematodes (watermelons are susceptible to root-knot nematodes); deters cucumber beetles; attracts beneficial insects
Repels cucumber beetles and squash bugs; trap crop for aphids; ground cover suppresses weeds and retains soil moisture; attracts pollinators IMPORTANT management caveat: without active management, nasturtiums can become a SOURCE of aphids that migrate to nearby crops. Either remove aphid-infested nasturtium plants promptly, or treat the trap crop itself to eliminate the aphid colony before it spreads. Strategic placement within 4-5 feet of protected crops is key.
Aromatic oils repel cucumber beetles and spider mites; low-spreading ground cover reduces weed pressure
Repels cucumber beetles; quick spring crop harvested before watermelons sprawl; minimal competition
Attracts pollinators for watermelon flowers; provides light windbreak for young plants; avoid dense planting , watermelons need full sun
⚠️ Keep Apart (4)
Same pest profile concentrates cucumber beetles, squash bugs, and powdery mildew; cross-pollination affects seed saving but NOT current year's fruit
Allelopathic , strongly inhibits watermelon growth
Potatoes compete aggressively for nutrients and water; potato harvest disturbs watermelon roots; both heavy feeders
Aromatic interference may inhibit watermelon growth
💊 Medicinal Uses
Medicinal Properties
- Extremely high in lycopene (especially red-fleshed) , the same antioxidant in tomatoes; higher concentrations in watermelon than tomatoes per serving; linked to reduced prostate cancer risk and heart health
- Contains citrulline , amino acid that converts to arginine, improving blood flow; may reduce muscle soreness and support cardiovascular health
- Excellent hydrating food (92% water) with natural electrolytes (potassium, magnesium) , natural 'sports drink'
- Good source of vitamin C, vitamin A (beta-carotene), and vitamin B6
- Seeds: rich in zinc, magnesium, iron, and healthy fats; traditional remedy for kidney and urinary tract health (diuretic effect)
📝 Growing Notes
Watermelon (Citrullus lanatus) is a DIFFERENT species from melons (Cucumis melo) , they don't cross-pollinate. Originated in Africa , extremely drought-tolerant once established due to deep taproot. Four types: Allsweet/Oblong (large, striped , classic 'picnic' melons), Icebox (small, round , 'Sugar Baby'), Seedless (triploid hybrids , need a pollinator diploid variety nearby), and Yellow/Orange flesh (sweeter, more honey-like). Ripeness tests: 1) Tendril nearest fruit stem turns brown and dries, 2) Ground spot (where melon rests on soil) turns from white to creamy yellow, 3) Thumping produces a dull, hollow sound (practice required). Powdery mildew is the main foliar disease. Striped and spotted cucumber beetles spread bacterial wilt. Trellising possible with sling support for smaller varieties.
🛒 Buy Seeds & Plants
Baker Creek Heirloom Seeds
Johnny's Selected Seeds
Botanical Interests
True Leaf Market
Burpee
Territorial Seed Company
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