We stock Sagittaria japonica which has ‘single’ three -petalled flowers and the double, and more attractive, Sagittaria japonica ‘Flore Pleno’. Neither has done particularly well for us in our pond. We have replanted them in different positions this year. We noticed that new shoots are prone to water snail damage, so it is important to keep water snails off them early on. We sell a very effective ‘litter picker’ device which is great for removing snails.