Sky-blue with bright gold centres
27 Dec 2007
Nymphaea nouchali, commonly known as the blue water lily, is South Africa’s most commonly grown indigenous water lily and is a must have for any water garden.

The blue water lily is a clump-forming perennial with thick, black, spongy, tuberous rhizomes anchored in the pond mud by spreading roots. The large flat leaves are rounded or oval in shape and can measure up to 40 centimetres in diameter.

They start out small and soft at the centre of the plant, and as they age they are pushed towards the outer perimeter, making room for new growth. The leaves are relatively short lived and are replaced regularly throughout the growing season. When the leaves start to die they turn yellow then brown and eventually disappear under the water. The blue water lily can spread over an area of about one metre.

The star-shaped flowers are displayed about five to eight centimetres above the water at the tip of a sturdy green stalk and appear almost constantly from spring until the end of summer.

The flowers are an elegant sky-blue colour and in the centre there are blue-tipped bright golden yellow stamens.

The flowers of the blue water lily open early to mid-morning and close completely in the late afternoon, staying closed all night. The opening and closing mechanism of these flowers is controlled by the sepals. If they are removed, the flower loses its ability to close.

A fully opened flower can measure up to 15-20 centimetres across and each flower lasts for about four days.

The lovely scent of the flowers attracts beetles, bees and many other small insects. In the wild, hippos, baboons and monkeys eat the exposed tubers.

The Wattled Crane, Pygmy Goose and Purple Gallinule enjoy the fruits that are produced. An amazing sight to watch is the African and Lesser Jacanas trotting over the leaves with their specialised feet feasting on
beetles and the other insects that inhabit the flowers.

The blue water lily can be found naturally in pools, dams, lakes and rivers from the Cape northwards, right through tropical Africa to Egypt.

One of the most common uses of the blue water lily is as a food source. In Namibia the tubers are peeled and boiled or roasted like potatoes. In Zimbabwe they are eaten raw. In other areas the flower heads and the seeds are eaten.

In earlier times in South Africa, the tubers were collected and eaten, either raw or in curries, particularly in the Cape by the Cape Malays and farming communities.

Today, only waterblommetjies are still eaten. Extracts from the flower in low doses are said to be a stimulant or aphrodisiac.

For medicinal purposes, the roots are dried and crushed to form a powder which is used to treat asthma, coughs and colds.

The easiest method of propagation is division. Lift and divide the plant just before the new growth commences in spring. Pull or cut the fleshy roots apart and replant them immediately in fresh soil.

Remember, each new plant should have at least one bud at the tip of the rhizome. The blue water lily may be grown from seed, but this requires extreme patience, for the plants take three to four years to flower.

Seed collection is extremely difficult, because the seed pods burst without much warning and the seeds disperse and sink quite quickly.

Before planting the blue water lily in your pond there are three very important things to remember. They require full sun. This is necessary for the plant’s growth and flowering. They must be planted in at least 30 centimetres of still water. They do not like a pond with a fountain or fast-moving water.

Lastly, they need to be sheltered from the wind as they are not very wind tolerant.

The most commonly used planting methods are planting the plant directly in the pond floor, making sure that there is a layer of sand and compost about 15 centimetres lining the base of the pond, or they can be planted in a specially manufactured plastic basket and sunk into the pond. These containers are available from most garden centres.

The blue water lily is an amazing and beautiful aquatic plant and is a must for every sunny water garden.

If you don’t have a pond do not despair, as many innovative gardeners with small gardens and sunny courtyards have made it possible to enjoy them. They have been successfully grown in a variety of water-filled pots, wooden barrels, old kitchen sinks and water features.

• Sonja van der Merwe is an indigenous plant enthusiast and owner of Springvale Nursery and Gardening.