Water lilies need plenty of sunshine in order to thrive, and will not flower if in shade or near moving water, so try to keep them away from fountains, waterfalls and pumps.
It is however important to choose the right variety as some of the larger, more invasive specimens are quite unsuitable for small garden ponds.
Lilies spread out more if planted on the pond bed where their roots can find natural nutrients. However, if they are planted in baskets or containers, there must be holes in the sides to allow the roots to spread and pebbles on top to weigh down the pot and prevent fish from uprooting them.
As lilies grow faster in warmer water near the surface, when planting put them no deeper than 12" using upturned buckets or bricks to create the required depth. Later on when the new lily pads have reached the water surface, lower them in to deeper water. The best time to plant is between May and June.
Water lilies in baskets can exhaust their nutrient supply by the second or third year. If their leaves turn light green or yellow or the flowers become small, this is a sign that they need feeding. Special water lily fertilizers are available and come in pellet form; these are simply pushed into the soil around the roots and will not upset the nutrient balance of your pond.
The ideal lilies for small ponds, water features are the dwarf varieties. Planting depth for these is from 20cm to 40cm:
Nymphaea Pygmaea Rubra Nymphaea Pygmaea Dwarf Helvola Nymphaea Pygmaea Candida
For a medium sized pond, larger than 2m x 2m go for medium sized varieties. Planting depth is 40cm to 60cm:
Nymphaea Alba Nymphaea Chromatella Nymphaea Marliacea Carnea Nymphaea Rembrandt Nymphaea Sioux