Water lilies (Nymphaea) are a genus of hardy and tender aquatic plants. Visible from March to September, they bear flat, plate-like leaves that sit on the water’s surface, from which pink, yellow or white flowers appear from June to September. There’s a huge variety of waterlily plants to choose from – most do best in large ponds and lakes but there are some dwarf types that can be grown in small garden ponds.
Waterlilies are an important part of a balanced pond. They offer shade and protection to fish and a place to hide from herons. The flowers are also attractive to pollinating bees.
How to grow waterlilies
Waterlilies need still water and full sun. Choose the right waterlily for your pond – there are several types, with each type requiring a specific planting depth. Place your waterlily on a 20cm-deep brick ‘plinth’ initially, and gradually lower it over the growing season. In autumn, trim back dead foliage of hardy waterlilies and let them die back to the bottom of the pond. Lift tender waterlilies and keep them somewhere frost free over winter.
More on growing waterlilies:
Where to plant waterlilies
Waterlilies will thrive only in a pond that has still water and gets plenty of sunshine. If you have a bubble fountain, position the water lily as far away from this as possible.
In this clip from Gardeners’ World, Carol Klein visits Bennetts Water Garden in Dorset to look at a variety of waterlilies, including our native British Nymphaea alba, as well as cultivated varieties such as star-flowered white ‘Hermine’ and red ‘Escarboucle’ – a slow-grower that’s ideal for a medium-sized pond:
How to plant waterlilies
Plant waterlilies from April to September. When choosing a waterlily for your pond, make sure you select the most appropriate size. Typically, large waterlilies should sit 75cm below the surface; medium waterlilies 50cm below and small waterlilies 20cm below. If you plant them too deeply they will fail to flower, too shallow and they will die. If your pond is too deep for your waterlily to grow successfully, add bricks to achieve the ideal depth (be careful not be pierce the liner, here).Water lilies are not often sold at garden centres, so contact a specialist grower for a full range.
If your pond has a solid liner, plant your water lily in an aquatic basket. Line the basket with a piece of hessian and fill it three quarters full with aquatic compost. Place the waterlily rhizome in the basket and cover with more compost, ensuring that the crown is at soil level. Top off with a layer of lime-free pea gravel. The gravel will stop the compost floating to the surface.
When planting your waterlily, don’t plant it at its final depth straight away, as this can shock and kill the plant. Initially, place it about 20cm below the surface – preferably on a ‘plinth’ of bricks – and then gradually remove lower the depth, by removing bricks, over the next month.
About 10 days after planting your waterlily, you should see new leaves appearing at the surface. If you don’t you may have planted the waterlily too deeply.
n this short clip, Monty Don shows you how to place waterliles on a pile of bricks, then gradually remove them, to lower the plants as their stems grow:
How to care for waterlilies
Hardy waterlilies require very little care. Remove faded foliage in autumn to prevent a build up of nutrients in the water, which can lead to algal blooms.
Tender waterlilies should be lifted out of the pond before the first frosts, and kept in a light and frost-free place over winter. Keep them submerged in water in a large tub, and follow the specific growing instructions given to you by the specialist nursery.
If you’re growing a waterlily in a pot, feed plants in spring by pushing a specialist aquatic feed tablet into the compost.
Most waterlilies should be divided every five years.
How to propagate waterlilies
After about five years, water lilies will be ready to divide. They often stop flowering when they have outgrown their container. Lift the plant out of the pond in March. This is a smelly and tricky job so wear waterproof trousers and ask a friend to help. Turn the plant out of its container. With a sharp knife, remove sections of rhizome with at least two eyes per section and repot them. Ideally place them back into the pond straight away. The tough woody crown of the old plant can be discarded.
Growing waterlilies: problem solving
Green/brown water lily aphid can cause problems for waterlilies in large numbers, but they rarely cause significant damage.
Great waterlily varieties to try
- Nymphaea pygmaea ‘Alba’ – a dwarf type for a small pond. Enjoys shallow water (20cm). White flowers from June to September. Ideal for a small pond pot. Hardy.
- Nymphaea ‘Pygmaea Helvola’ – ideal for a small pond. Pale yellow flowers from July to September. Slightly fragrant. Spread of up to 45cm.
- Nymphaea ‘James Brydon’ – pink flowers in July and August. Ideal for a medium pond with a spread of 1m. Hardy.
- Nymphaea alba – white flowers from June to September. A native that is ideal for natural, deep and large ponds. A spread of 2m. Fully hardy.
- Nymphaea ‘Marliacea Albida’ – For a large pond with a spread of 120cm. Fragrant, double white flowers from June to September.
- Nymphaea ‘Escarboucle’ – For a medium or large ponds – spread 1.2m – 2m. Vermillion flowers from June to September.