Growing Watermelons: Sweet Summer Giants

Watermelons are the ultimate summer fruit - sweet, juicy, and refreshing on hot days. While they require warm conditions and plenty of space, growing your own watermelons is incredibly rewarding and easier than many gardeners think.

Getting Started

Seed Starting

  • Start indoors 3-4 weeks before last frost in cooler climates
  • Sow directly when soil temperature consistently exceeds 21°C (70°F)
  • Plant seeds 2-3cm deep in well-draining soil
  • Use biodegradable pots if starting indoors - watermelons dislike root disturbance
  • Seeds germinate in 7-14 days in warm conditions

Varieties to Consider

Small/Personal Types (space-saving):

  • ‘Sugar Baby’ - 6-8 pounds, dark green, red flesh
  • ‘Golden Midget’ - yellow skin, early maturing
  • ‘Bush Sugar Baby’ - compact vines for small gardens

Traditional Large Types:

  • ‘Charleston Gray’ - oblong, gray-green skin, sweet flesh
  • ‘Crimson Sweet’ - round, light green with dark stripes
  • ‘Moon and Stars’ - heirloom with unique spotted skin

Seedless Varieties:

  • ‘Triple Sweet’ - seedless with excellent flavor
  • ‘Mini Love’ - small, seedless, perfect for families

Growing Conditions

Soil Requirements

  • Well-draining, sandy loam with pH 6.0-6.8
  • Rich in organic matter but not overly fertile
  • Warm soil that heats up quickly in spring
  • Raised beds or hills improve drainage and soil warming

Light and Temperature

  • Full sun (8+ hours daily) essential for sugar development
  • Very warm-season crop - requires 21-32°C (70-90°F)
  • Needs long, warm growing season (80-100 frost-free days)
  • Cannot tolerate any frost

Watering

  • Consistent moisture during vine growth and fruit set
  • Provide 2.5-3.8cm (1-1.5 inches) weekly during growth
  • Reduce watering 1-2 weeks before harvest to concentrate sugars
  • Water at soil level to prevent foliar diseases
  • Mulch to retain moisture and warm soil

Care and Maintenance

Planting Method

  • Plant in hills or mounds 1.5-2m apart
  • Each hill can accommodate 2-3 plants
  • Use black plastic mulch to warm soil in cooler climates
  • Provide plenty of space - vines can spread 3-4 meters

Support and Training

  • Allow vines to sprawl naturally
  • Support developing fruits with boards or straw to prevent ground rot
  • Can be grown on strong trellises if space is limited
  • Turn fruits occasionally for even ripening

Fertilizing

  • Apply balanced fertilizer (10-10-10) at planting
  • Side-dress with compost when vines begin to run
  • Reduce nitrogen as fruits develop to promote sugar content
  • Potassium important for fruit quality and disease resistance

Pest and Disease Management

Common Pests:

  • Cucumber beetles - use row covers, yellow sticky traps
  • Aphids - encourage beneficial insects, use insecticidal soap
  • Squash bugs - hand-pick, remove egg masses

Disease Prevention:

  • Choose disease-resistant varieties
  • Ensure good air circulation
  • Avoid overhead watering
  • Practice 3-4 year crop rotation

Harvesting

Signs of Ripeness

  • Ground spot (where melon touches soil) turns creamy yellow
  • Tendril nearest to fruit stem dries and turns brown
  • Dull, hollow sound when tapped
  • Surface becomes dull rather than shiny
  • Fruit stops growing and vine begins to decline

Storage and Handling

  • Harvest carefully to avoid bruising
  • Store whole watermelons at room temperature for 1-2 weeks
  • Cut watermelon keeps in refrigerator for 3-5 days
  • Can be cubed and frozen for smoothies

Companion Planting

Good Companions

  • Beans - fix nitrogen early in season
  • Corn - provides light shade in very hot climates
  • Nasturtiums - trap crop for aphids and squash bugs
  • Radishes - help deter cucumber beetles
  • Oregano - may help repel pests

Plants to Avoid

  • Tomatoes - compete for nutrients and attract similar pests
  • Potatoes - heavy feeders that compete for nutrients
  • Cucumbers - share pest and disease problems

Troubleshooting

Common Problems

  • Poor fruit set - inadequate pollination, plant bee-attracting flowers nearby
  • Fruit cracking - irregular watering, maintain consistent moisture
  • Bland flavor - insufficient heat or too much water near harvest
  • Sunscald - protect fruits with shade cloth during extreme heat

Solutions

  • Hand-pollinate if bee activity is low
  • Maintain consistent watering schedule
  • Use reflective mulch to increase light and heat
  • Provide adequate space for air circulation

Maximizing Success

Climate Considerations

  • Cool Climates: Use black plastic mulch, row covers, start indoors
  • Hot Climates: Provide afternoon shade, consistent moisture
  • Short Seasons: Choose early-maturing varieties, start indoors

Space-Saving Techniques

  • Choose bush or compact varieties
  • Train vines vertically on strong supports
  • Grow in large containers (minimum 150L/40 gallons)
  • Use intensive planting methods in raised beds

Seasonal Care

Spring

  • Prepare soil with compost and organic matter
  • Warm soil with black plastic before planting
  • Start seeds indoors in cooler climates

Summer

  • Maintain consistent watering during growth
  • Monitor for pests and diseases
  • Support developing fruits

Fall

  • Reduce watering as fruits ripen
  • Harvest before first frost
  • Save seeds from best fruits

Growing watermelons successfully requires patience, warmth, and space, but the reward of perfectly ripe, homegrown watermelon makes the effort worthwhile. Nothing beats the sweet satisfaction of a sun-warmed watermelon from your own garden!