For either formal or informal pools, the water lily, perhaps, should be the first considered, for it is the queen of the water garden. The first essential for successful cultivation is still water. Waterlines found growing wild are always in the backwaters of rivers away from running water. They must also have plenty of sun and air, and are therefore admirably suited to our formal pools. Theshould be given adequate water surface, so that they do not become crowded, for the water lily increases in size very rapidly, sometimes doubling its growth in one season.
Thefor water lilies is the same as already mentioned for aquatics in general. Peat and -mould must be avoided, as also must sand. When planting be sure to make the very firm and only fill the pool by degrees, as the extend in length. It is advisable to leave the same water in the pool for as long as possible, only changing it if it becomes really dirty, as the older and stiller the water the more luxuriant the growth.
As the plants become too big for theirthey can be lifted and divided, this operation being carried out in May; otherwise the plants can be left in throughout the year.
Reeds are favourite plants for the formal pool, the tall, erect growth contrasting well with the floating form of the water lilies, but there is an exceedingly large variety of aquatics suitable for the pool, whether it be formal or informal.