Traditional Black Washington Watermelon

20 Seeds

Traditional Black Washington Watermelon is a vigorous heirloom variety that produces large, round to slightly oval fruits with a dark green to nearly black rind and sweet, juicy, deep red flesh. It is highly valued for its refreshing flavor and excellent keeping quality. Watermelon is rich in vitamins A and C, lycopene, potassium, antioxidants, and water, making it an excellent summer fruit. This warm-season crop thrives in the Gulf when planted during the appropriate season with full sun and well-drained soil.

Best Planting Time

• February to April (recommended for spring harvest)
• August to September (for autumn harvest in suitable Gulf areas)
• Avoid sowing during the coldest winter weeks and the peak summer heat.

Seed Preparation

• Soak seeds in lukewarm water (25–30°C) for 6–8 hours before sowing.
• No cold stratification is required.
• Optional: Soak seeds in seaweed extract to encourage stronger seedlings.

Soil Preparation

Use fertile, sandy, well-drained soil rich in organic matter.

Recommended mix:

• 40% Garden soil
• 30% Compost
• 20% Coco peat
• 10% Perlite or coarse sand

Ideal soil pH:

• 6.0–7.2

Sowing Method

• Sow seeds directly into the ground or large containers.
• Plant 2–3 seeds per planting hole.
• Sow seeds 2–3 cm deep.
• After germination, keep the strongest seedling and remove the weaker ones.

Temperature & Light

• Ideal germination temperature: 25–32°C
• Ideal growing temperature: 24–35°C
• Requires 8–10 hours of direct sunlight daily.

Watering

• Keep the soil evenly moist during germination.
• Water deeply when the top 3–5 cm of soil becomes dry.
• Reduce watering when fruits begin to mature to improve sweetness.
• Avoid wetting the foliage to reduce disease.

Germination Time

• 5–10 days

Plant Spacing

• 100–150 cm between plants.
• 200–300 cm between rows.
• Provide plenty of space for vines to spread.

Harvesting

• Harvest 80–100 days after sowing.
• Fruits are ready when:
  • The tendril nearest the fruit turns brown and dries.
  • The underside (ground spot) changes to creamy yellow.
  • The rind becomes dull and resists scratching with a fingernail.
  • The fruit produces a deep, hollow sound when tapped.

Fertilization

• Apply a balanced fertilizer every 2–3 weeks.
• Switch to a fertilizer higher in potassium and phosphorus once flowering begins to improve fruit quality.

Gulf Climate Tips

• Grow during the moderate temperatures of spring or early autumn.
• Apply organic mulch to conserve moisture and keep fruits clean.
• Avoid excessive nitrogen after flowering, as it promotes vine growth instead of fruit production.
• Water consistently during fruit development but reduce irrigation just before harvest.
• Monitor for aphids, whiteflies, spider mites, and powdery mildew.
• Traditional Black Washington Watermelon grows successfully in home gardens, farms, raised beds, and large containers with adequate space and sunlight.