Easily grown in organically rich loams in calm water margins in full sun. Winter hardy to USDA Zone 4 as long as the roots do not freeze (i.e., water does not freeze down to the roots). For water gardens or small ponds, plant roots in large containers or planting baskets with up to 24? of water covering the crowns. Container grown plants are easier to control and, if desired, to move to other locations. For naturalizing in larger ponds, roots may be anchored directly in the muddy bottom near the water margin where, once established, they will spread and colonize. In fall, containers submerged in very shallow water (less than 6?) should be moved into deeper water or brought indoors (basement, root cellar or other frost-free area) for overwintering.