"Instead of throwing away those watermelon rinds, turn them into a sweet treat with sugar, mint, and sweet basil. If you like, you can roll the dehydrated candy pieces in coarse sugar. Eat immediately or store in the freezer for up to 1 year."
Cut watermelon rind into 2-inch long, 1-inch wide, and 1/2-inch thick pieces.
Combine water, sugar, spearmint, and basil in a large pot. Bring to a rolling boil. Strain out spearmint and basil. Add watermelon rind, making sure pieces are completely immersed. Cook until rind is soft, about 5 minutes.
Drain watermelon pieces and arrange in a single layer on dehydrator trays. Dry according to manufacturer's instructions until pieces are candied and dried, 6 to 8 hours.