Obviously, the location of a pool (in sun or shade, warm climate or cool), its size (some plants would smother a miniature pool in a few weeks), and its design should be considered in selecting plants to grow in or with it. In fact, very tiny pools carefully placed to catch an artistic reflection may be better without any plant embellishment.
A frequent error is overplanting, with the water surface covered by a confusion of foliage and flowers, the perimeter a jungle. In small pools one pygmy lily is plenty; it needs clear, open water to set it off.
For pools of all designs—formal, contemporary, informal—plants are seldom arranged in neat rows, groups that repeat themselves regularly, or matching masses in perfect symmetry. The closest to formal balance might be adding accent and height by placing the tallest plant in the center of a formal pool. More often, it’s effective in one corner or at one side.
Few plants offer such striking variation in the forms available to create interesting patterns and dramatic contrast. There are flat, leathery leaf pads and slim, spiky swords; glorious china-like cup flowers and fluffy plumes; modest creepers and bold elephant leaves. Seldom does a flower-arrangement artist have such a wealth of exciting material with which to make her prize-winning compositions.
Miniature Water Lilies
Of the two general types of water lilies—tropical and hardy—the tropicals are least likely to be in scale with miniature pools. The leaves and flowers are larger, the leaves spreading out wider and the flowers standing out higher. The tropicals need lots of sun and warmth, can be shocked into dormancy if the water chills, and are usually treated like annuals and planted fresh, each summer. Some can be propagated from viviparous plantlets that grow on the leaves.
Among hardy water lilies there is a selection of pygmies with four-inch leaves and two-inch flowers in many colors—white, yellow, pink, red, and bicolors, some with attractively marbled foliage. Given generous sunshine, warm quiet water, and good nourishment, they will flower from July to frost, and can be held over the winter either outdoors or in.
In our area we set out hardy water lilies in late April or early May. If a late cold snap occurs when the plants arrive by mail, we keep them moist until it’s over. Since the roots are hardy only if they do not freeze, and since it’s difficult to keep small pools from freezing, each lily is planted in its own box, which is set on small stones or blocks so it is raised off the floor of the pool. Or plant in soil at the bottom of a tub-pool that will be taken up in fall. Lay the rhizome horizontal, with its growing tip out of the soil. Cover the surface with a web of clean sand, to keep the soil from muddying the water. If the plant is leafed out and the leaves don’t reach the surface of the pool, they’ll lengthen their stems in a few days.
For best growth and flowering, a pygmy lily needs at least a third of a bushel of soil and about eight inches of water over its crown. Soil can be heavy and clay-like, or average garden loam. If possible, add one-fourth the quantity of well-rotted cow manure—no other kind. Experts recommend strongly against the use of other-than-cow manures, swamp muck, leaf mold, peat moss, sand, or lime.
Lacking cow manure, you can get fertilizers prepared specially for water lilies, or you can use commercial garden fertilizers like those with 5-10-5 analysis. Supply nourishment at planting time, and once again a month or so later. Wrap balls of rotted cow manure, or handfuls of commercial fertilizer, in thin paper (a paper napkin will do) and thrust them down into the soil around the roots. Water lilies have voracious appetites, and even the pygmies eat heartily. On a starvation diet, they’ll stop growing and flowering.