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How to Germinate Watermelon Seeds

By Jenny Harrington ; Updated September 21, 2017

Juicy, sweet watermelon is truly a summer treat. Watermelons require a long, hot summer in order to reach maturity. In the areas with short summers, start watermelon seeds indoors and transplant outside after all danger of frost has passed. In areas with a long summer watermelon can be started right in the garden bed. Germinating and then growing the seeds into the melons is not challenging but does require ongoing maintenance throughout the season for a successful harvest.

Fill individual seed starting containers with potting mix to start seeds indoors three weeks before the final frost date in your area. Moisten the soil before planting the seeds.

Sow two seeds per container for standard watermelon varieties or one seed per container for seedless varieties. Plant seeds 1 inch under the soil surface in the center of the pot.

Cover pots with plastic wrap and place in a warm room to germinate—approximately 75 to 80 degrees Fahrenheit. Check daily for sprouts and to ensure the potting mix is still moist. Watermelons usually take 7 to 14 days to germinate but check seed package for exact timing for the variety you are growing.

Remove plastic wrap once sprouts appear and move pots to a warm, sunny window. Keep potting medium moist at all times and do not let it dry out—watermelons require a lot of moisture to grow properly.

Transplant into weed-free garden beds once all danger of frost has passed and seedlings have produced their second set of leaves. Plant outside 3 feet apart in rows that are 7 feet apart.


Things You Will Need

  • Pots
  • Potting soil
  • Plastic wrap


  • If starting seeds directly in the garden bed, wait until all danger of frost has passed and the soil has warmed to 60 degree Fahrenheit. Place black plastic over the bed and cut a small hole in the plastic to sow each seed.
  • Choose short season varieties of watermelon if you live in an area with a short growing season.
  • Use a growing heat mat to ensure proper soil temperature inside if necessary.


  • Avoid starting watermelon seeds indoors too soon as large seedlings don't transplant well.
  • Seedless varieties must be planted with seeded varieties as the seedless ones cannot self pollinate.
  • Watermelons require a lot of water to grow properly. Do not let the soil in the garden bed dry out, especially during the heat of summer.

About the Author


Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications. Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.