The selection of a site for your pond usually amounts to deciding where it will look best; actually, however, there are few places where a pond won't look and do well. The only limiting factor to any site is the amount of sunlight that falls upon it. Hardy water lilies require a minimum of four hours of sun a day. The more they get, over and above that, the more vigorously they will grow and the better they will bloom, but in any spot where they get the four-hour minimum they can be depended upon to give satisfaction. The tropicals won't do their best with less than five or six hours of sun daily.

Night-blooming tropicals require as much sunlight as any of the others. Contrary to what seems to be a popular opinion, they draw only moral support from the moon.

If you are doubtful about a site, check it, by all means, before you get started. If you have a spot in mind and there are other flowers there now, rest assured that water lilies will do as well or even better.

Otherwise, stretch out a length of garden hose or clothesline in a figure the size and shape you want for your pond and in the place you have selected. Then check the spot several times during a day when the sun is shining, and you will know all you need to know about sun requirements. If the shifting shade of a tree barely edges out the needed amount of sunlight from an otherwise desirable spot, a little judicious pruning may let in enough sun to allow you your preferred location.

A word of warning about trees. I tell customers every year that a water lily planted under a tree will not bloom. It will produce foliage, but it will not bloom. At least once a year somebody sends in a letter that makes a liar out of me. Often the letter is accompanied by a snapshot of a water lily blooming beautifully from a tub or barrel in the deep shade of a spreading tree. All I can say, into the teeth of such challenges, is that these are freak blooms that just happen, like the dandelions that sometimes come up in February. Believe me, there is no such thing as a "shade" species of water lily. If there were, and I had access to it, I could retire comfortably after one season of selling it.

A pond directly under a tree is, therefore, out of the question. Even a pond partially under a tree is to be avoided if possible. Leaves and other matter dropping from a tree generate gas as they decompose in the pond, and this gas retards - frequently kills - fish. Oak leaves, probably the worst of the lot, give pond water a strong acid content within a few days.

If it is practical for you to locate your pond so that it is protected from the north by a building, a line of trees, a hedge, or similar windbreak, I would advise you to do so. Shelter from northerly winds, particularly in early summer, will give your water lilies a better chance for an early, healthy start. I would recommend only a casual effort to provide this protection, however. I don't think I would go to the trouble of planting a windbreak if I had none.

The only other consideration in selecting a site is that of filling and emptying the pond. Filling it entails only the business of running a garden hose out to it from the nearest water tap. Emptying isn't much more difficult. Since we shall discuss drainage in detail later, let it suffice at this point to say that the closer the site is to lower ground, to or through which water might be emptied by gravity, the simpler the drainage arrangement of a pond can be.

Aesthetically speaking, there are two types of ponds-formal and informal.

A formal pond may be practically any severe and regular shape. Obviously it should suit a man-made decorative scheme. Formal ponds can be very beautiful, as our illustrations show, but they should not be attempted if there is little space. The slightest suggestion of crowding ruins the effect of a formal pond.

The informal pond may have just about any kind of outline, although a regular, or at least uncomplicated, shape is likely to be the most pleasing. Through the clever arrangement of marginal plants, the informal pond appears to be a work of nature.

There is also the completely natural pond, the spring-fed pond where you have only to plant water lilies to convert the site into a garden. The natural pond is rare and stands in a class by itself. I will discuss its possibilities in more detail in Chapter 8 on planting.

Whatever the style of pond decided upon, I strongly recommend a simple shape. Stars, triangles, extreme kidney and crescent shapes and the like are bad. By no stretch of the imagination do they fit in with any kind of formal landscape, and it is next to impossible to give them the natural appearance an informal pond should have. Moreover, the more intricate the pond form, the more difficult it will be to build.