General Culture:

Winter hardy to USDA Zones 5-10. Needs full sun for best flowering. Set out plants, tubers or runners in spring in mud at the margins of a pond or in containers in a water garden, either along the shore or in up to 6-12” of water. Seed may be sown in spring or fall. Seed may also be collected and sown in containers resting in dishes of shallow water. Plants will naturalize by rhizomes and self-seeding, but are not considered to be invasive. Promptly deadhead spent flowers to prevent any unwanted self-seeding.

Noteworthy Characteristics:

Arrowhead, duck potato or wapato is a vigorous, deciduous, marginal aquatic perennial that typically grows 1-4’ tall. It is noted for its arrowhead-shaped leaves and three-petaled white flowers in whorls of three. It commonly grows submerged in shallow water or out of water on wet muddy banks. It is native to sloughs, swamps, marshes and margins of streams and ponds throughout North America including Missouri. Each plant produces leaves and flowers on separate stalks. Leaves can be quite variable in size. Emersed leaves (to 12” long) are typically broadly sagittate (arrowhead-shaped). Submerged leaves are often much narrower (linear to ovate). Three-petaled white flowers appear in whorls of three atop stalks rising to 4’ tall. Male flowers have bushy yellow center stamens and female flowers have mounded green centers. Plants bloom freely from July to September. The common names of duck potato and wapato are in reference to the enlarged rounded starchy golfball-sized tubers that form at the ends of underground plant runners (rhizomes). When dislodged from the mud, these tubers will float to the surface. They are edible, and may be boiled or baked and eaten as a potato-like food. Native Americans harvested and consumed these tubers, which in some areas were known as wapato. The tubers are also an important food source for waterfowl, hence the name duck potato. Seeds are attractive to many water birds. Arrowhead is commonly used in pond restorations.

Problems:

No serious insect or disease problems. Watch for spider mites and aphids.

Uses:

Water or bog gardens. Pond edges.

© Missouri Botanical Garden, 2001-2009