Watermelons are warm weather plants, and seeds are best sown when all threat of frost has passed and the soil has reached 60 degrees Fahrenheit. In northern Indiana, that is from mid-May to June 1, depending on the region.
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Sandy Mitchell is an Ohio-based writer, blogger and editor. Among other projects, she writes for About.com and "The Better Drink." Before devoting herself full time to writing, Mitchell was a travel agent and cruise school instructor for 18 years. She holds a Bachelors of Science in business administration from Bowling Green State University.