Nasturtium officinale, commonly known as watercress, is a perennial, edible aquatic herb that is native to Europe and Asia. It often grows as an annual and is currently a member of the family Brassicaceae. Watercress is botanically related to its less famous relatives, garden cress, mustard and radish ? all noteworthy for their peppery, tangy, zesty, piquant flavor. It definitely adds a boost in vitamin C and iron, to sandwiches, omelets, baked fish and fresh salads. Watercress grows between 15.2cm and 5.7cm high and needs water to grow. Plants grow quickly, developing long stems that bear multiple compound leaves of rich green. From late spring to midsummer, clusters of tiny, white flowers appear at the stem tips. These attract butterflies and bees. Grow watercress in full to partial sun. Plants thrive in rich, sandy or muddy soil with a neutral pH along shallow pond edges, stream edges, or in moist gardens. They tolerate light submersion as long as water is fresh and clean. Watercress may also be grown in containers if the water is kept fresh through consistent repeated changing. Watercress prefers cold water. Leaves are edible raw or cooked. Water cress is mainly used as a garnish or as an addition to salads, the flavour is strong with a characteristic hotness. It has a reputation as a spring tonic, and this is its main season of use, though it can be harvested for most of the year and can give 10 pickings annually. The seed can be sprouted and eaten in salads. The seed is ground into a powder and used as a mustard. Hardiness zone: 3 - 9