Jubilee watermelons grow 25-40 pounds (11-18 kg) on average

Jubilee watermelons are large, oblong heirloom varieties typically weighing 25-40 pounds (11-18 kg) and measuring 12-18 inches (30-45 cm) in diameter. Their size depends on growing conditions, spacing, and care, with some reaching 50+ pounds (23+ kg) under ideal circumstances.

Typical Size Range of Jubilee Watermelons

  • Weight: 25-40 lbs (11-18 kg), with record specimens exceeding 50 lbs (23 kg).
  • Length: 15-24 inches (38-61 cm) from stem to blossom end.
  • Diameter: 12-18 inches (30-45 cm) at the widest point.
  • Shape: Elongated oval (oblong) with a slightly tapered end.

Factors Affecting Jubilee Watermelon Size

  1. Soil Quality: Rich, well-draining soil with compost boosts growth. Poor soil stunts size.
  2. Watering: Consistent moisture (1-2 inches/week) prevents cracking and supports expansion.
  3. Spacing: Vines need 5-6 feet (1.5-1.8 m) apart to avoid competition for nutrients.
  4. Pollination: Adequate bee activity ensures proper fruit development.
  5. Growing Season: Long, warm summers (80-90°F/27-32°C) maximize size.

Jubilee vs. Other Watermelon Varieties (Size Comparison)

Variety Average Weight Shape Days to Maturity Ideal Use
Jubilee 25-40 lbs (11-18 kg) Oblong 90-100 Fresh eating, large gatherings
Crimson Sweet 15-25 lbs (7-11 kg) Round 80-85 Home gardens, picnics
Sugar Baby 8-12 lbs (4-5 kg) Round (icebox) 75-80 Small households, containers
Carolina Cross 50-100 lbs (23-45 kg) Oblong 95-105 Competitions, large families

How to Estimate Jubilee Watermelon Ripeness by Size

  • Color: Creamy yellow underside (where it touches the ground).
  • Tendril Check: Nearby tendril turns brown and dries.
  • Sound: Hollow "thump" when tapped (not dull or metallic).
  • Size Plateau: Growth slows after reaching full size (check daily).

Tips for Growing Larger Jubilee Watermelons

  1. Prune secondary vines to direct energy to 1-2 main fruits per plant.
  2. Use black plastic mulch to retain soil warmth and moisture.
  3. Fertilize with low-nitrogen, high-phosphorus mix (e.g., 5-10-10) at flowering.
  4. Support melons with slings or straw to prevent ground rot and misshaping.
  5. Harvest before first frost-cold temperatures halt growth.