WATERMELON - Citrullus lanatus. Grow in light, rich soil with plenty of organic matter incorporated into the soil. Dates to maturity are from direct seeding in the garden. Water regularly during the growing season. Cut back or discontinue watering when melons are ripening. Melons need consisistently warm soil or the plants will be stunted and the yields reduced. Use plastic row covers, garden blankets or a dark mulch to maintain soil temperatures. Ripe watermelon sound hollow when thumped; the rind touching the ground will be yellow white. Approximately 500 to 800 seeds per ounce or 17 to 28 seeds per gram.