Saving the seeds off of your Bradford watermelon is easy! As you eat your watermelon, simply place your seeds in a colander and rinse in cool water until they are clean and free of any pulp. Spread the seeds out on a sheet of newspaper thinly and allow to dry. Try folding a seed in half to check for dryness. Seeds should snap when dry. Once dry, place in an airtight container and store in the refrigerator. If stored properly, they will keep for many years.