Nymphaea, common name 'Water Lily' is one of the most beautiful pond plants and not difficult to grow. Like so many pond plants it needs to be planted in sterile compost and in a basket to contain the plant, soil and roots. Water lilies are deciduous, and require full sun.
Many Lilies are fully hardy although there are some tender varieties which makes it is important to check when buying a named variety. There are many which are scented including the aptly name Nymphaea Odorata, the fragrant water lily.
Perhaps the most important point when planting lilies into a pond is to plant to the correct depth, which varies from variety to variety, from around 30cms - 90cms. This means you need to select a lily which can achieve the correct planting depth in your pond. If your pond is releatively shallow you will need to select a lily which will thrive planted at a lesser depth. The depth is measures from the top of the basket to the water surface. Plant directories give the recommended depth for different types of lilies.
Lilies also need to be divided regularly as they are vigorous and grow to a good size. You can generally tell when the lily is due, or overdue for dividing, as the leaves start to bunch and don't lie flat on the pond surface, image center left. If left the leaves will become more congested and flowering will reduce.
Below are some illustrations of a lily which we left way too long before dividing and it was hard work.
The lily was huge under the water surface, like an iceberg or small floating island. It had signficantly outgrown it's basket as can be seen from the image where the basket is just a small part of the plant.
Dividing it was difficult it was heavy, and had to be manhandled to the side of the pond and pieces hacked off it with a saw until small enough to lift out.
It was then possible to separate out some roots and leaves, disgarding the rhizome which was massive and very woody. It's a good idea to keep the new plants wet in a tug or bucket until you are ready to replant. The new plants were re planted and have quickly established themselves; the rest is disguarded. Had the plant be devided more regularly, the job would have been much easier.
Water lilies like so many pond plants are vigorous and dividing will check their growth.