Of all the aquatic plants that grow in our ponds, it is the waterlily that epitomizes the subject to many people. To my mind there are few plants -aquatic or land-based - to compare with the pure exotic pleasure that a succession of waterlily flowers can bring.
Fortunately for waterliliophiles like me, there are plenty of varieties to choose from; the sad thing is that the majority of them grow too big for the small ponds that most of us possess today. It is for this reason that in the early 1900s the French hybridist Latour-Marliac, amongst others, devoted himself to the creation of newer and better miniature or dwarf varieties, many of which are classed under the category known as the Pygmaea hybrids.
Tragically, he took much of his cross breeding data with him to his grave, but at least he left us with a fabulous range of small and compact varieties, even if the plant parentage of most of them is not fully known.
The pygmy waterlilies are excellent for sinks, troughs or ponds where the water is no deeper than 30cm (12in). Most will grow contentedly in just 10cm (4in) of water, or even in the deeper marginal shelves of a larger pond.
There are really just two notes of caution when it comes to growing these small and compact varieties. The first concerns the likelihood of the plants freezing in winter: despite being hardy, the aquatic plants grow in very shallow water which, in the harshest of winters, can freeze solid. The plants should, therefore, be provided with sufficient depth to ensure that the rhizomes remain unfrozen during the coldest spells. Ii this is not possible, they should be protected, either by draining the pool in autumn, and then covering the lily with thick straw, or by lifting the plant in mid-autumn and keeping it in water in a frost-free place until planting time again.
The second warning is not so serious for the plant, but by ignoring it you could be forfeiting some excellent color, with resultant substandard aquatic plants. Small waterlilies are perfect for growing in contained water features, such as a barrel, tub or sink, but there is a temptation for many of us to fit a small ornamental fountain, or a regular drip-drip feature of some kind. All waterlilies, of whatever size, dislike moving water around their leaves and stems (which suppresses flowering), and this problem can be exacerbated in a container.