How to Grow Watermelon
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🛠️ Supplies You'll Need
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🌿 Plant Overview
☀️ Growing Requirements
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Sun
Full Sun (8+ hours)
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Water
Regular (1-2 inches/week)
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Spacing
72" apart
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Depth
1" deep
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Height
12-24"
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Germination
4-12 days
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Common Watermelon Varieties
Popular cultivars to look for at your local nursery or seed supplier.
Crimson Sweet
The standard round watermelon with bright red, sweet flesh and a tough rind that ships well.
Sugar Baby
Compact 8–12 lb "icebox" watermelon ideal for small gardens and refrigerators.
Orangeglo
Orange-fleshed heirloom with exceptionally sweet, honeyed flavor.
Yellow Doll
Small, early-maturing watermelon with creamy yellow flesh and mild, sweet flavor.
Moon and Stars
Beautiful heirloom with dark green rind dotted with yellow "stars"; red or yellow flesh.
Days-to-maturity figures are approximate and vary by climate and growing conditions.
Common Watermelon Problems
What to watch for — and how to fix it before it spreads.
Pests
Transmit watermelon mosaic virus; dense colonies weaken vines.
Reflective mulch deters aphids early; spray with insecticidal soap; encourage beneficial insects.
Feeds on young plants and spreads bacterial wilt; worst on seedlings and transplants.
Row covers until vines are well established; kaolin clay; pyrethrin for severe infestations.
Scar fruit skin and transmit tomato spotted wilt virus; especially damaging in dry conditions.
Apply spinosad; use blue sticky traps; water consistently to reduce stress.
Diseases
Dark, water-soaked lesions on stems that exude amber-colored gum; common in wet summers.
Avoid overhead watering; apply copper fungicide; rotate crops; use resistant varieties.
Soil-borne fungus causing yellowing, wilting, and death; plants decline despite watering.
Plant highly resistant varieties; rotate for 5–7 years; improve drainage.
Dark, sunken lesions on fruit; pink spore masses in wet weather; spreads through seeds.
Use certified disease-free seed; apply copper fungicide; remove infected plant debris.
Common Mistakes
Watermelon is a tropical crop; cold soil causes stunting, poor germination, and disease.
Wait until soil is 70°F+; use black plastic mulch to warm soil; direct sow never before last frost.
Cutting unripe watermelons is heartbreaking and irreversible.
Check the tendril nearest the fruit — when it turns fully brown and dry, the melon is ripe. Also look for a creamy yellow ground spot.
Vines can spread 10–15 feet in every direction.
Give each plant 6–8 feet of space in every direction; choose icebox varieties for small gardens.
🌾 Seed Saving Guide
🟡 ModerateWhen to Harvest Seed
Ripe eating watermelons have fully mature seeds — save seeds from fruits you harvest to eat.
Processing
Rinse seeds in a strainer to remove pulp, spread flat to dry for 2 weeks.
Seed Viability
Up to 5 years when stored cool, dark, and dry.
Pro Tip
Watermelon crosses with citron melons but not cantaloupes. Isolate by 500 feet from other watermelon varieties.
Seed Storage Supplies
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Raised Bed Planting Guides
A 4×8 bed fits 0 plants of Watermelon. See plant counts, spacing grids, and companion pairings for every bed size →
Watermelon Planting Calendar by Zone
Watermelon Planting Calendar by State
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Frequently Asked Questions
When should I plant Watermelon? +
Start Watermelon seeds indoors 4 weeks before your last frost date, then transplant outdoors 2 weeks after the last frost. Use the search on this page to find exact dates for your ZIP code or city.
How long does Watermelon take to grow? +
Watermelon typically matures in about 80 days from planting. Exact timing varies by variety, soil conditions, and local climate.
Should I start Watermelon indoors or direct sow? +
Watermelon should be started indoors 4 weeks before the last frost date. This gives seedlings time to establish before being transplanted outside after frost danger has passed.
How much sun does Watermelon need? +
Watermelon requires full sun (8+ hours) to thrive.
How far apart should I plant Watermelon? +
Space Watermelon plants 72 inches apart to allow adequate airflow and root development.
How much water does Watermelon need? +
Watermelon has regular (1-2 inches/week) water needs. Consistent moisture is important especially during germination and early growth.
Can you save seeds from Watermelon? +
Yes — seed saving difficulty for Watermelon is rated moderate. Ripe eating watermelons have fully mature seeds — save seeds from fruits you harvest to eat. Rinse seeds in a strainer to remove pulp, spread flat to dry for 2 weeks.
How long do Watermelon seeds last in storage? +
Properly dried and stored Watermelon seeds remain viable for up to 5 years. Store in a cool, dark, dry location in an airtight container with a silica gel packet for best results.
Are Watermelon seeds open-pollinated? +
Yes — Watermelon is open-pollinated, meaning seeds saved from your harvest will grow plants true to the parent variety. This makes it an excellent candidate for building a self-sustaining garden.
About Watermelon
Sweet summer fruit that needs warm soil and long growing season. Reduce watering as fruits ripen.
Expect your Watermelon to be ready for harvest in approximately 80 days from planting.
Use the search above or browse by zone or state to find the perfect planting dates for your location.