While not florally outstanding – some have noat all – this group contributes to the control of algae by surface coverage. Some float all the time, some only for brief periods. Some spread prodigiously; in small pools these are easily controlled by netting but they can be a menace in very large pools. No conventional planting is required: these are the plants that are ‘just dropped in’. A general stocking guide is one plant or portion for every 10 sq. ft. of surface area.
The stocking rates recommended are those which have been found satisfactory for initial planting in order to establish pool balance in a reasonably short time. After two or three years the growth of some plants may need thinning or reducing, particularly of oxygenators. The idea that this could be avoided by planting a smaller number initially has little merit; it would mean waiting very much longer before there was sufficient plant growth to cope with the algae.
The novice water gardener cannot be expected to make much sense of a long list of totally unfamiliar plant names. For his benefit most specialist suppliers have worked out, for pools of various sizes, complete collections which include the appropriate numbers of the different plant types, and probably snails as well. Some choice ofcolours will probably be offered. For any size of pool alternative collections at different prices are generally available. The cheapest alternative is likely, in the nature of things, to contain easily propagated varieties. This does not necessarily mean that they lack horticultural merit, but it does imply that they may be rather ordinary, and probably vigorous and invasive growers. The most garden-worthy plants are seldom the easiest to , and the choicest varieties cannot reasonably be expected in the cheaper collections. Bearing in mind that aquatics are perennials that go on year after year, the best long-term yield of gardening pleasure will come from an investment in the choicest plants.
Aquatic plants can easily be sent by post, but will be fresher if you can arrange to collect them from the grower. If you favourplanting, but feel unsure of your own planting skill, some suppliers will arrange for your order to be planted in containers all ready for you to collect – at a price, of course. Some specialists now offer a selection of lilies, marginals and oxygenators already established and growing in containers, a quite different thing from planting up your order just before you arrive. These established plants, planted in the previous season and thoroughly rooted, can be moved complete with container without the slightest check or risk of transplanting loss. They can also be moved at any time of year because no disturbance is involved. The cost of this sort of instant pool furnishing is two or three times that of taking normal plants and doing it yourself. And there need be no shyness about doing your own planting because it is perfectly simple, involving no rare expertise.