The best way to grow and care for water lilies
GEMMA NEECH – formal ornamental team leader at RHS Garden Wisley – gives HANNAH STEPHENSON a guide to growing water lilies and types to look out for.
Water lilies are rhizomatous aquatic perennials that like relatively still water in full sun, flowering in summer. In the wild, they can be found growing in bot tropical and temperate climates, but for the UK, it is best to choose a hardy cultivar from a specialist supplier, and one suited to the size of your pond, as some are more vigorous than others.
The best time to buy and plant is around February or March. Make sure they have a healthy crown and there are signs of new shoots and leaves emerging.
MAINTENANCE AND CARE
THEY can be planted or grown in pots, in which case they need dividing every two to three years and feeding to boost growth and flowering. The ideal time to divide is in February or March while they are dormant. Use a sharp old bread knife to cut through the rhizomes and while dividing, look out for healthy white roots and firm rhizomes – if you see black roots, they will be dead and soft rhizomes mean they have rotted.
PESTS, DISEASES AND OTHER PROBLEMS
THE main pest is water lily beetle. Its larvae are small and black and eat elongated holes through the leaves in summer. The only thing that can be done is to hose them off with a jet of water.
HARDY OPTIONS
■ Nymphaea ‘Gladstoniana’: Vigorous with large, rounded, dark bronze-tinged leaves 17-20cm wide star-shaped creamy-white flowers and prominent yellow stamens.
■ Nymphaea ‘James Brydon’: Rounded, dark purple-blotched, bronze-green leaves and 12cm cupped, carmine-red flowers 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.