Icebox Watermelons


Three people placing watermelon halves in crates.

Watermelons (Citrullus lunatus) are in the family Cucurbitaceae and are divided into types based on their weight: personal (<6 lbs), icebox (6–15 lbs), and picnic (>15 lbs). Watermelon arrived in the Americas in the early 1600s with traders and was first cultivated in Massachusetts in 1629.  Until 1980s, watermelons were considered a seasonal fruit, but today imports combined with local production ensure a year-round supply. Icebox watermelons are gaining in popularity as they are ideal for small families and fit easily into a refrigerator.

Our program at WSU Mount Vernon NWREC focuses on evaluating:

  1. The diversity of watermelon flesh colors.
  2. Early maturing varieties that are suitable for production in the  relatively cool climate of Northwest Washington.
  3. Use of grafting to prevent soil-borne diseases that are common in our cool climate.


This publication serves as a general budgetary outline for establishing and producing seedless watermelon in Washington.

People look at halved watermelons on a long table.
Watermelon field day.

Research Reports

  • 2016 Research Trial (PDF). In 2016 we evaluated 28 varieties of watermelon grown at the Washington State University Mount Vernon Northwestern Washington Research and Extension Center.
  • 2006 Research Trial (PDF). In 2006 we evaluated 117 varieties of watermelon. The field was certified organic and was managed accordingly.
  • 2005 Research Trial (PDF). In 2004 we evaluated 44 varieties of icebox watermelon, and in 2005 we evaluated 101 varieties. The field was certified organic and was managed accordingly.
  • 2004 – 2005 Variety Descriptions (PDF). This table includes information for each variety in our trial in 2004 and 2005. Information includes days to maturity, fruit size and weight, rind color, flesh color, ploidy, brix, and seed sources.
  • 2004 Icebox Watermelon Rind Thickness (PDF). In 2004, we measured the rind thickness of 47 icebox watermelons. Rind thickness may impact suitability for shipping as well as consumer preference.
  • 2004 Research Trial (PDF). 44 varieties of icebox watermelon were grown and evaluated in a replicated field study. The field was certified organic and was managed accordingly.
  • 2003 Research Trial. This was an observation study (non-replicated) and included 9 varieties of icebox watermelons. The study was conducted on certified organic land and was managed accordingly.
  • 2013 Cost Estimation of Producing Seedless Watermelon in Eastern Washington (PDF). WSU Extension Fact Sheet FS150E. 6 pages. Published October 2014. In addition to the publication there is a Microsoft Excel worksheet available. To download the worksheet, use the following link Cost 2013 ( XLSX).

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