These may be planted just as they start into growth, usually about May 1 in the vicinity of Philadelphia; at that time all danger of frost is over and even the tender kinds may be safely set out.
Only sufficient fresh water need be supplied to the pool to provide for that lost through evaporation.
The Nelumbiums are very handsome, of easy culture and well suited to large pools. Other good aquatic plants are the Water Hyacinth, Water Snowflake, Papyrus or Umbrella Plant.
The hardy varieties may be left in the pool all Winter; but they require a protection of leaves, with evergreen boughs or boards over them to keep the leaves in place.
It is well to stock garden pools with goldfish to destroy mosquito larvae, and to add the requisite touch of life and color.
The loss of so many of the old-time swimming holes has developed a demand for the artificial swimming pool.
Fig. 143. - Swimming pool within the garden area. Gray sandstone coping to match the walls and steps.
Such pools may often be placed within the garden area (Fig. 143).
The construction should be the same as that outlined for smaller pools, care being taken to waterproof the walls, not only from the standpoint of keeping the water within the pool, but to keep the moisture from outside from seeping through and discoloring the walls. The swimming pool may be incorporated in the flower garden as a wading pool or made sufficiently deep at one end to allow of diving, running from two to three feet deep at one end to from seven to eight feet deep at the other.
Swimming pools should be provided with a ladder to assist in leaving the pool at the deep end. A removable ladder is best for a combination garden and swimming pool. Rings should be supplied at intervals along the edge of the pool and a rope run through, so that bathers may grasp same for support when required.
Should the water supply come from a spring or stream on the premises it will be necessary to have a valve or plug to shut off the supply at the intake. When using water from a stream it is advisable to have a forebay set at one side and the pipe run from that to the pool. The forebay or well is built along the stream to prevent leaves, sand and debris from getting into the pipe. This is essential, regardlesss as to what method is adopted for conveying the water to the pool, either by gravity, ram, gas engine, electric pump or gasoline engine.
As swimming pools must be emptied frequently in order to cleanse them, a small electric pump may be introduced, where the power is at hand, and the water from the pool connected to the garden pipe line and so used for watering, thus conserving the general supply.