May 19, The Bradford boasted sweet flesh so coveted, 19th-century growers turned to guns and poison to thwart thieves. The melon all but vanished by. Jul 18, You can always continue to call watermelon a fruit in the privacy of your want to call them, here's how to grow your watermelons super sweet. 'Cream of Saskatchewan,' a super-sweet white-fleshed heirloom watermelon, weighs four to 10 pounds and ripens in about 80 days. So does 'Sweet Siberian' .