Slice 12 oz. peeled fresh ginger into 1/4-inch pieces.
Place in a pan with 1/3 cup sugar and 3 cups water; stir until sugar dissolves. Bring to a boil, cover, remove from heat and let syrup steep for 30 minutes; strain.
Mix syrup with 2 (12 oz.) cans of frozen lemonade concentrate and amount of water called for on cans.