DESCRIPTION: These hardy and tender, bog and aquatic plants are commonly known as Arrowhead. They are great for the perimeter of pools and water gardens and for tanks or tubs in the greenhouse. The leaves are shaped like an arrowhead, thus the common name, and they produce tall spikes of pretty, white flowers, ½- to 1-inch in diameter, from June to October. S. sagittifolia, Common Arrowhead, is a hardy variety native to Europe and Asia. It produces underground tubers that are eaten in the Orient. It produces arrow-shaped leaves up to 18 inches long and white flowers. Its double-flowered variety, flore-pleno (it's sometimes called S. japonica), produces double flowers that bloom for a longer period. S. graminea var. Crushed Ice is a variety with beautiful green leaves variegated with creamy white. S. latifolia, Duck Potato, of North America is another hardy kind that grows about 4 feet tall and produces little tubers at the ends of its roots that attract waterfowl. Its arrow-shaped leaves can grow up to 32 inches in length. Three-petaled, white flowers are produced in whorls of three, in the summer. S. montevidensis, Giant or Aztec Arrowhead, is a tender native of South America that grows 2 feet or more high. Its flowers are produced in clusters at the ends of stems all year round. They are white, each painted with a dot of crimson at the base. This plant is considered a short-lived perennial, but it provides an abundance of seeds to be sown. In cold regions, it can be wintered indoors where it will go through winter dormancy. S. lancifolia, Lance-Leaved Arrowhead, also found in South America, grows up to 20 inches high and produces dark green, spear-shaped leaves. Its white flowers are centered with yellow. Its variety Rubrum has red-stems. S. natans, Dwarf Sagittaria, is a native of North America. It is commonly seen along the Atlantic Coast from Maine to Florida. This variety grows submerged beneath the water's surface. It produces dark green, grass-like foliage that is rounded at the tip. The leaves are from 2 to 12 inches long. In shallow water, ovoid-shaped, floating leaves are often produced on the water's surface and sometimes linear, aerial leaves with obtuse tips. White flowers float on the water's surface. It may be difficult to establish in a pond with larger fish and may need some protection, but soon should be growing vigorously.
POTTING: The tender kinds can be grown outdoors, year-round, in the far South; otherwise, they can be wintered indoors in a greenhouse having a minimum temperature of 50º F. When these plants are grown outside, a sunny position, or one with partial shade, at the edge of a pond should be provided. They can be planted in the fall or early spring in 2-gallon containers filled with loam and well-decayed manure. The tubers, compost and a large stone can also be enclosed in a piece of burlap and dropped in the water. They can be set in up to 18 inches of water; S. latifolia and S. sagittifolia should be grown in water up to 6 inches over the crown. Once they are planted, they need no further attention, except to make sure they don't surpass their designated space by pulling out the wayward shoots in early summer. The tender varieties that are planted in a greenhouse, in tubs or tanks, should have the same soil mixture of loam and decayed manure, which is placed in the bottom of the container, 12 inches deep. Place the tuberous roots just under the surface and cover with an inch of sand. The tub or tank is filled with water and the plants aren't disturbed until they begin to become crowd. When that happens they are removed and a few of the healthiest tubers are repotted in fresh compost. S. natans, the Dwarf Sagittaria, is grown underneath the water. It roots shallowly and absorbs nutrients from the soil and the water. It may be weighted down and set in the water to sink or it can be planted in pots of pea gravel to anchor it down. It will survive the winter as long as it is below the ice levels of the water. It may be necessary to prune it down to prevent the ends from freezing.
PROPAGATION: These plants may be divided or seeds may be sown. S. montevidensis is a variety that produces plenty of seeds that can be started in moist flats of soil. The seedlings should have water covering their crowns. S. latifolia produces tubers at the ends of its roots that may be detached and planted an inch under the mud. S.natans sends out short runners that form new plants.
VARIETIES: The hardy kinds - S. sagittifolia; S. japonica; S. latifolia; S. graminea & var. Crushed Ice; S. natans.
The tender kinds - S. montevidensis and S. lancifolia & var. rubrum.