Where a natural pond is subject to a sudden increase in water volume, a water gate connected with an open ditch or culvert of sufficient size to divert the additional column of water must be built to obviate damage from floods. This sort of construction work is often complicated and had best be left to professionals, as in the end it will most generally be found a good deal cheaper, and will save much annoyance and disappointment.

If more than one pond is projected, connect them with each other by drains, making each a little lower than the preceding. With such an arrangement, water can be supplied from a fountain in the first pond, which may be entirely ornamental. This has the advantage that the sun’s rays heat the water drops in falling. Further, since it is chiefly the surface water which is carried off, the water in the last pond will have the highest temperature. This pond can then be selected for the growing of tender or heat-loving tropical nymphaeas, etc. Even the giant Victoria Cruziana does well in such an unheated pond in St. Louis, for example, but in more Northern regions, some means of artificial heating would have to be installed to help out.

Ponds built entirely of brickwork or concrete offer certain serious objections. In the first place, their banks cannot be planted. Besides, where the winters are very cold, projecting brick or concrete walls must be protected, and it is only where the ponds form part of a formal plan, that the grey masonry edges, projecting half a foot or more above the ground, are appropriate. As a general rule, a combination of concrete and puddling is to be preferred.

For a brick and cement pond, excavate to a depth of two and one-half feet. The sides are given a circular slope, which forms an angle of about 45° with the perpendicular. After the floor has been thoroughly levelled, bricks are laid and cemented into place. Then the walls are built in the same way. They must reach to within one foot from the bottom. The whole is finally covered with a one-half-inch finishing coat of cement.

The slope above the brick wall must now be covered with puddled clay, thoroughly pounded into place, allowing the clay generously to overlap the cement. It is not necessary for the puddled clay closely to follow the outlines of the pond; for this combination of brickwork and clay allows of a planting of the edges of the pond and some plants demand more space than others, and some even must be allowed to grow out at will if they are to look acceptable. This is true for the majority of plants used in the water garden, one great charm of which lies in the unforced contour lines. When finished, the pond will be about two feet three inches deep.

A water supply must now be arranged. This can come from a faucet, which is a good deal better than a fountain, since a continual spray is not good for water-lilies and has a tendency to give them a bedraggled appearance.

A low fence, constructed of perforated pipes and connected with the water system, may surround the pond. This will very effectually flush the pond, but is not necessary since a single faucet through which the water can be turned on from time to time is amply sufficient to remove any scum which may accumulate on the surface of the pond. Of course an overflow, connected with a drain or silt-pit, must be provided. This should be placed in position before the laying of the foundation is begun. A narrow drain pipe will be sufficient for all requirements.

The bog garden consists merely of very wet ground in which a host of interesting plants flourish. It must, of course, be beside a pond or along a stream. In spring the brown woolly fronds of cinnamon fern will first show themselves, uncoiling as they rise. The swamp rose-mallow (Hibiscus moscheutos) will give a wealth of great white or pink flowers in mid-summer. In autumn blue mists of asters or a yellow glow of coreopsis and dazzling shafts of cardinal flower (Lobelia cardinalis) will brighten the spot.

HANDLING CUT FLOWERS

Water-lilies do well as cut flowers if they are properly handled. The flower selected for cutting must be newly opened or just about to open. In nature the life of each bloom is limited to three or four days, but in the house it may keep a day or two longer. Occasionally death seems to overtake the motor centres while the flower is still open, and then it remains several days before the petals wither.

The new flower may be recognised by these features: (I) The stamens spread apart at the centre of the flower, leaving a free passage down to the stigma; (2) the anthers are plump and round and have not yet begun to shed any pollen; (3) the basin-like stigma is filled with liquid excreted from its surface.

The flower stalk is scarcely able to supply the petals with water; the cut flower should be floated in a dish or, if placed in a vase, the vase should be full to the brim with water, the flower projecting as little as possible. When carried from the sunny garden into the house the flower is likely to close, on account of the diminished light, but it will open again next morning as well as if it were outside.

From a surface of sixteen square feet, about a bucketful of water escapes every day by evaporation and transpiration of the plants. Stagnation is prevented by having a few fish and some submerged plants like Cabomba or Myriophyllum. It is therefore very easy to care for a garden up to six by twelve feet, even with only a bucket to supply water.

On the other hand, a large pond fed by a natural stream will often be in danger from floods. Unless the stream be very small in proportion to the lake it will be necessary to have means of diverting it into a culvert or sluice on occasion.

Floating parts of plants have very remarkable powers of accommodation to the depth of the water. Water-lily leaves may be entirely submerged in the evening, and by next morning their stalks will have grown just enough to spread them on the surface again. But on all considerations, it is desirable that the water level should not vary more than four inches at the most; even this amount may bring into view ugly strips of mud or masonry. An outlet of ample size is as necessary as an inlet for the regulation of the water supply.

Small ponds on level or gently sloping ground may be allowed to overflow their sodded margins. If fed by a continuous open stream, it may be most artistically led away in a similar manner, either directly, or by a waterfall, or through a bog garden.

It is doubtful whether it is easier to build a pond in a natural waterway, or to make it from the foundation up. Unless the natural water course can be easily diverted it will usually be better not to use it. For every stream at a distance of a hundred feet or more from its spring head is subject to flooding from heavy rains.

Should a violent current sweep over and among our aquatics it would destroy all the tender plants, break down our lotus, papyrus, and the like, and cover everything around with a thick layer of mud, and the season’s hopes would be gone. We shall do best, therefore, to secure a more even supply of water. A good spring will suffice for anything except Victoria and the tender waterlilies. Indeed, south of Philadelphia, spring water will materially help many of the hardy nymphaeas to endure the summer heat.

Lacking a spring, water may be drawn by a pipe or sluiceway from any near-by stream. The sluice will of course be so arranged by gates or by position of intake, as to avoid the flooding of the pond in case of freshets. But, after all, the easiest plan is to draw the water from a pipe with a spigot. It is not necessary to maintain a continuous flow and change of water. Just as a balanced aquarium will go for weeks or months without attention, so it is with the pond. It is only requisite to replace the water lost by evaporation and leakage.

It is in the treatment of the margin that we make or mar a pond’s natural beauty. There is no one way in which native waters always meet the land, but there are some ways in which they never do. Nature never made broad borders of concrete or brick or hewn stone. Therefore avoid these in making a water garden. Rough stone walls are permissible at inlet and outlet only and even here they may be avoided if clayey soil can be had, provided the bank can be made proof against crawfish, which is most important. And in place of stones there will spring up beds of moisture-loving mosses, liverworts, and smooth sheets of Pellaea, whose delicate fruit-stalks shoot up in the first warm days of spring.

Beside the pond itself a path of gravel will enable us to come close to the water’s edge. Now we must bend away from the water and around the bog garden; now we cross It on a stone causeway or rustic bridge.

All around the grass and flowers run right out to the water’s edge. This is the essential point, and perfectly easy to attain. The water-tight construction of the bottom of the pond only needs to come up to the height of the desired water level. From this point a grassy bank may be raised as steep and high as one desires. Four to six inches above mean water level is high enough.

We can hide the junction of land and water completely by means of water-clover (Marsilia). This curious fern-plant, with leaves like a four-leaved clover, grows equally well in the wet edge of the sod or in the pond to a depth of eighteen inches. In the former situation the leaves stand up three or four inches, in the latter they float.

It does not offend if the small tank takes some conventional shape. A sunken tub is essentially round, and a wooden or iron box will unavoidably be square-cornered. A brick or concrete construction, if not over ten feet long, may be rectangular. But if possible avoid geometry in the garden. A bald circle with a gaping ring of cement between the sod and the water is not a thing of beauty, though ponds of geometrical figure edged with stone coping are effective in formal gardens.

Possibly the best of all is a narrow, curving pool, like the bed of some slow stream. Let it widen out here and there into broad, open stretches if you wish. At the ends, also, or in shallow pockets on the side, the water may give place to a bog garden. On the north side a thicket of trees and shrubs may come out to the water’s edge. But keep the south side clear, so as to admit every available ray from the sun.

A pond of water-lilies is a possibility for anyone who can give two square feet of water surface in a sunny spot, and it should be near at hand so that you can easily see the flowers when they are at their best. All the hardy water-lilies must be enjoyed in the morning or early afternoon; for the flowers close at specific times for each kind, varying from noon to four, or at the latest five, o’clock. The tender kinds fall within two distinct classes, there being both day bloomers and night bloomers.

Half a barrel will make a thoroughly practical” lily-pond” for the smallest garden! Cut this to a depth of eighteen inches, fill two-thirds with a rich, heavy soil, and sink so that the bottom is three inches below the level of the ground, for though the leaves and flowers love sunshine, the black ooze in which the roots naturally live is always cool.

But one need not stop here. Only space and inclination limit the number of barrels that may be utilized for this purpose. Arrange them so that the whole will form a figure of irregular outline and leave some space between the individual barrels. These spaces, perhaps a foot to eighteen inches wide, offer situations well suited to the needs of a variety of water-loving plants, such as forget-menots, Lysimachia and others, which will form a framework to set off the beauties of the water-lilies.

Not all the barrels need contain waterlilies, however. One or two may be devoted to other plants such as water hyacinths, water poppies and the like, while taller plants, like Cyperus Papyrus and nelumbiums tend to relieve the flatness necessarily incident to a water garden. The latter, however, grow quite tall and can be used most effectively in large gardens; and they also look best in masses.