What's more, there are so many types for virtually every size of water feature, from an old wooden barrel to a huge pond. The beautiful flowers bloom from May until November, and many of them have a light fragrance. What they all need, though, is sun.
Gemma Neech, formal ornamental team leader at RHS Garden Wisley, offers a guide to these glorious water-loving plants...
Conditions they need
Water lilies are rhizomatous aquatic perennials that like to grow in relatively still water in full sun, flowering in summer. In the wild, water lilies can be found growing in both tropical and temperate climates.
They have leaves varying in size, from small to gigantic, up to 3m in diameter - these giants (Victoria Amazonica) grow in the tropics and they are very impressive.
Choosing and buying
If growing water lilies, it is best to choose a hardy cultivar from a specialist aquatic supplier, and choose a cultivar suited to the size of your pond or lake, as some are more vigorous than others.
The best time to buy and plant is late winter or early spring, around February or March. As with buying any plant, make sure water lilies have a healthy crown and there are signs of new shoots and leaves emerging.
Maintenance and care
They can be grown in The ideal time to divide water lilies is in February or March whilst they are dormant. A sharp old bread knife is a good tool for cutting through the rhizomes when dividing water lilies, but no specialist tools are required.
When dividing, look out for healthy white roots - if you see black roots, they will be dead. Select firm rhizomes, not soft ones, which are likely to have rotted.
Pests, diseases and other problems
The main pest we find on water lilies at Wisley is the water lily beetle. Its larvae are small and black, eating through the leaves in the summer. The result is a patchwork of elongated holes in the leaves. The only thing that can be done is to hose them off with a jet of water.
Hardy types to consider
Nymphaea 'Gladstoniana': A vigorous aquatic perennial with large, rounded, dark bronze-tinged leaves and star-shaped creamy-white flowers 17-20cm wide, with prominent yellow stamens.
Nymphaea 'James Brydon': Rounded, dark purple-blotched, bronze-green leaves and cupped, carmine-red flowers 12cm in width, with orange stamens.
Nymphaea 'Escarboucle': Round, floating leaves 20-25cm in width, and fragrant, cupped orange-red flowers to 20cm across, with orange stamens.
Nymphaea 'Gonnere': A compact aquatic perennial with bronze-tinged young leaves and globose, scented white flowers 15cm in width, with light yellow stamens.
Nymphaea 'Pygmaea Helvola': A miniature water lily with dark, purple-blotched, rounded floating leaves to 12cm in length, and cupped, fragrant, sulphur-yellow flowers 5cm across, with orange stamens.
Nymphaea 'Marliacea Chromatella': Purple-marbled floating leaves 15-20cm wide, and cupped light yellow flowers 15cm across, with orange stamens.