Zizania aquatica aka Indian Rice

Zizania aquatica is an annual grass in the Poaceae family. Its names include annual wild rice and Canada wild rice. It comes from central and eastern Canada and the United States. It is not native to Britain or Ireland. In the wild, it grows in shallow rivers and lakes. It favours sites where water moves at a slow pace.

This fast-growing grass reaches about 11.5 feet [3.5 metres] tall. Its stated spread is about 0.7 feet [0.2 metres]. It flowers from July to September. Each plant bears both male and female flowers, but in separate flowers. Wind carries the pollen between them. The seeds ripen from September to October. Plants spaced about 1 foot [0.3 metres] apart can form many flowering shoots. This tall grass has ornamental value in ponds and lakes.

Grow it in full sun, since it cannot grow in shade. It accepts sandy, loamy and clay soils beneath the water. It also tolerates mildly acid, neutral and mildly alkaline conditions. Water depth matters more than a narrow choice of soil. It prefers water about 0.3–0.7 feet [0.1–0.2 metres] deep. It can grow in depths reaching 3.3 feet [1 metre]. Avoid stagnant water. PFAF lists USDA zones 5–9 and reports that seeds survive freezing in ice.

Fresh seed must stay wet to remain viable. Dry seed may lose its ability to sprout within four weeks. Keep collected seed in water in a cool place. Sow in spring, with the pots beneath shallow water. Starting seed in a greenhouse helps bring germination forward. In Britain, self-sown plants may sprout too late to set seed. A stand can therefore fade despite producing seedlings. Early sowing improves the chance of harvesting grain there.

The cooked seed serves as a grain, much like rice. Indigenous North Americans have used it as a staple food. The long, black seeds also yield meal for bread or soups. They supply riboflavin and niacin. The bases of the culms, or grass stems, are also edible vegetables. PFAF reports no known hazards and lists no medicinal uses. It also lists no other uses beyond its food value. Its pond setting and tall growth give it a clear garden role.