Sgt. Volkin is the author of The Ultimate Basic Training Guidebook. The Ultimate Basic Training Guidebook is available (as of this writing)) in both book and e-book format at www.ultimatebasictrainingguidebook.com.
Step 1. Plant watermelon seed during spring once all danger of frost has passed in a location that receives full sunlight. Spread 3 inches of organic manure over the planting site and use a garden tiller to incorporate it into the soil to increase drainage and fertility.
However, watermelons need a long, warm growing season to flourish. Knowing when to plant watermelon will help you harvest a bounty of large ripe melons. Watermelons can grow in USDA Hardiness Zones 3 through 11 and need 70 to 90 days to reach maturity, depending on the variety. Soil temperatures must be at 60- to 65-degrees Fahrenheit at the 4-inch depth, or watermelon seeds will not germinate. Average air temperatures must be between 70 and 85 degrees Fahrenheit.