This section is from the book "How To Make A Flower Garden", by Wilhelm Miller. Also available from Amazon: The Well-Tended Perennial Garden: Planting and Pruning Techniques.
SOME years ago, in a low-lying meadow near my house, in Belmont, Massachusetts, I made an artificial pond in which to grow water-lilies - a modest affair seventy feet in length, and varying in width from five to fifteen feet. Here I planted several different kinds of hardy pond-lilies and other aquatic plants, some of which bloom from May until October. The venture has been so successful, and the little sheet of water has added such a charming feature to the landscape, that I am tempted to tell my experience as an amateur water gardener, that others may, if they wish, go and do likewise.
A bit of Mr. Underwood's water garden, showing Its relation to the house.
"The margin was well sodded, In order to secure a firm and moderately dry edge".
The meadow where the pond is situated was rather damp, and at times quite wet and boggy. The soil is a black and heavy peaty loam, with a subsoil of gravel and fine blue clay. This particular spot was naturally so wet and difficult to drain thoroughly that it seemed admirably adapted for this purpose, especially so as it was well protected at the north from the cold winds by a heavy growth of willow trees; while nothing intervened to the south to cut off the sun's rays, which shone all day upon it.
With these natural advantages in my favour, the work of building the pond seemed already well begun. In order to clearly show the outline, and to form some idea of what the shape ought ultimately to be, to conform with the lay of the adjoining land, stakes were driven into the ground at intervals of every two feet along the prospective margin, and the excavation of the soil was begun. Through the center of the pond the dirt was removed to a depth of five feet, well down to the gravel and clay. During the work of excavation, three blind or stone drains were encountered. They led into a meadow brook which flows close by, and, fearing that perhaps they might at times drain off the water from the pond faster than it would come in, particularly as the brook, only forty feet away, is nearly three feet below the level of the garden, and to guard against any possible loss of water in this way, the whole bottom of the pond was covered with four inches of well-puddled clay. This measure, of course, while it prevented any water from escaping, also served to keep out all ground water.
So, not wishing to depend entirely upon the rainfall for a supply, a line of two-inch iron pipe was laid from the pond, up to the bed of the small brook several hundred feet, to a point where a small dam held the water back about a foot above the level of the garden. This gave an abundance of water at all times, though all that is necessary is just enough to keep the pond fresh and make up for any evaporation.
At times it may become necessary to draw off the water from the garden, in order to set out new plants or to remove some varieties that are growing too fast and crowding out others. In order to accomplish this, a discharge pipe was run into the bed of the brook, and at its upper end was fastened into the bottom of a small tub placed in the deepest part of the pond, the tub being used to keep the mud away from the outlet and so prevent the pipe from being clogged. For an overflow, a brass standpipe was fitted into the outlet, and in order that the water might be kept at any desired level, this pipe was made in several sections which fitted one into another, and by putting in or taking out a number of sections the depth of water is easily controlled.
So near and yet so far.
Everything being in readiness, about eighteen inches of soil was replaced over the lining of clay, the slope of the bottom being made very gradual, particularly along the shores, that the conditions might be favourable for the growth of suitable marginal plants. On top of this natural soil was placed a foot of compost, made by thoroughly mixing two parts of the richest loam with one part of well-rotted cow manure. The balance of the excavated dirt was graded back upon the high land which formed the south shore of the pond. The land on the north, or lower side, was left at its original level, and by this treatment a most natural effect was secured. The entire margin was well sodded, in order to secure a firm and moderately dry edge, and a row of stepping-stones was placed between the outlet and the shore, thus bringing the overflow pipe within easy reach.
Our friends the frogs.
How mosquitoes breed in the absence of the goldfish.
Along the lower margin were set out marsh marigolds, and forget-me-nots, and different varieties of water-grasses. Arrow-head and pickerel-weed were also started along the grassy border, and all along the farther and broader end of the pond were grouped masses of large Japanese iris, to serve as a background for the water-lilies, which were to be the principal features of the water garden. When ready for planting, the water was drawn out of the pond until only a few inches remained. Planks were then placed upon the bottom, and, walking out upon them, I set out the lilies, pushing the rhizomes firmly down into the muddy soil.
After the plants were all in place, in order to keep the water as warm as possible until the new growth began, the pond was kept about half full. Then, as the tender foliage started and the lily-pads came near the surface, the level was raised a few inches at a time. Where it is not practicable to control the garden in this way, the rootstocks may be pushed down into the mud with a long pole; but the growth will be much more rapid and vigorous if, at the start, the water can be kept quite shoal and warm. The pond was first planted in May, and by the middle of August the lilies were well in bloom. They may be set out at any time during the summer, but an early start is necessary if they are to flower the same year.
There is another important and interesting feature of this pond that is of special significance: it has become the home of a large number of beautiful goldfish that have thriven and multiplied in its waters ever since the pond was started eight years ago. It is not generally realised, as it should be, that goldfish will live in our natural northern waters; for, as I shall show, their presence in many small ponds may be of vital importance to us. It is now known that a certain mosquito conveys from man to man the germs of malaria and yellow fever, and it has been found that water is absolutely essential to its life in the earlier stages. The mosquito lays its eggs upon the surface of some quiet pool, where, after a few days, they hatch out, filling the water with thousands of "wigglers," or larvae, and after another transformation eventually become the adult mosquito. To exterminate the mosquitoes, we must destroy their breeding places. Fill up or drain off the pools where the "wigglers" are to be found and, where it is not practicable to adopt either of these methods, cover the surface of the water with kerosene oil, thus cutting off the supply of air from the larvae and smothering them.
Goldfish feeding on mosquito larvae.
But what shall we do with the water garden, which appears so perfectly suited for raising mosquitoes? Shall we fill it up, drain it off, or pour oil upon its troubled waters? If his pond should prove as great a source of pleasure to the reader as mine has been to me, he will be loath to adopt any of these radical measures. Repeated and diligent search had failed to reveal the presence of any mosquito larvae in my pond, and this seemed all the more strange when, in the quiet waters of the brook not fifty feet away, I discovered thousands of active "wigglers." Reflecting upon this fact, it seemed probable that the goldfish were holding the mosquitoes in check in the pond, while in the brook the insects were breeding in comparative safety.
To test the correctness of this theory, I took two small goldfish from the pond and placed them in an aquarium where they could feed upon mosquito larvae and be under observation. The result was as anticipated. Whenever they were dropped into the water the "wigglers" disappeared in short order.
When it is once understood that goldfish are useful, as well as ornamental and comparatively hardy, it is to be hoped that they will be introduced into many small bodies of water, such as lily ponds and water gardens, where mosquitoes are likely to breed. In my experience, these fish can easily be reared in any sheltered pond where the water is shoal and warm.
What country town is there that does not have some swamps containing pools that are difficult and perhaps impossible to drain? Where it is possible, let every swamp be drained; but let no hasty judgment condemn and banish all quiet country pools, for many of them, by proper treatment, can be improved, and made not only wholesome but charming features of beauty in the landscape.