Lilypons, Md. — Within a week or so of helping to found the Water Lily Society of America recently, Charles Thomas met Gordon Ledbetter, the world-renowned expert on waterlily culture, from County Wicklow, Ireland. The result of that meeting was to remove ''of America'' from the society's title.
Apparently no appropriate society for waterlily growers existed anywhere else in the world - not even in Britain, where a higher share of gardeners grow waterlilies than anywhere else.
So now there is one Water Lily Society to serve the interests of growers worldwide. Its headquarters is now here in the United States, and the society's first international symposium is scheduled for Philadelphia next August.
Mr. Thomas, executive secretary of the infant society and president of Lilypons Water Gardens here, won't equate the international lily symposium to, say, the World Orchid Congress - at least not yet. But he believes emphatically that big things will eventually come from the group's small beginnings.
Growing waterlilies has already reached a mass group in Britain and is catching on fast here in the US - increasing by almost 25 percent a year, according to some industry estimates.
Why this growing popularity? For many reasons, according to Mr. Thomas, chief among them that waterlilies are easy to grow, produce exquisitely beautiful blooms, and flower prolifically.
Plant breeders have been active with waterlilies just as they have with other plant species, so that waterlilies now come in several sizes and in a wide range of colors - red, white, yellow, pink, and apricot in the winter-hardy species, plus all the foregoing, as well as blue, purple, and peach, in the tropical species. In the heavy frost areas of the world, the tropical varieties are grown as annuals.
Flower production is prolific from early June through September. Cut flowers last for three days in the vase, at which stage there are likely to be all the replacements you need down on the pond. Hardy waterlilies produce new flowers every week, while the tropical varieties do so every two or three days. Cutting, in fact, stimulates flower production.
''If you have waterlilies on your ponds you will always have them by the vaseful in your house,'' Mr. Thomas says.
Modern materials, principally in the form of polyvinylchloride (PVC) piping, swimming pool liners, fiber glass, and just plain polyethylene sheeting, make it simple to construct a pool. Some folks even grow lilies on apartment balconies, such is the availability of appropriate containers.
Weeding presents few problems in a pool (dandelions refuse to grow there), and if you keep a few fish in the lily pond you'll even lower the mosquito population in your garden. How? Wandering mosquitoes deposit their eggs in the pool, only to have the larvae eaten by the fish.
In his book ''Water Gardens'' (Alphabooks, Sherborne, Dorset, England), Gordon Ledbetter lists among his reasons for the growing popularity of the waterlily culture the fact that the plants are so easy to grow. He writes that ''a garden pool probably offers more certain and more rapid results than any other form of gardening.'' The lily pool, he contends, ''involves less maintenance than theequivalent area of grass.''
These are the basic cultivating essentials for waterlilies:
Sun. The more the better (some varieties can tolerate more shade than others).
Water. The surface of the water should be 6 to 18 inches above the container top. Avoid water motion close to the lilies (waterlilies do not grow in a moving stream, but will do so in the quieter coves).
Soil. Use heavy garden soil containing a moderate amount of clay. Avoid commercial potting mixes and anything containing insecticide or herbicide.
Containers. Pans, pails, or baskets.
Spring and summer maintenance. (1) Fertilize monthly for vigorous growth and flowering; (2) prune away old leaves; and (3) divide every 2 years - and every year if the growth is vigorous.
Winter maintenance. (1) Stop fertilizing; (2) prune dead leaves and stems; (3 ) place lily container (which stands on bricks during the growing season) on pool bottom after frost; and (4) if the roots are likely to freeze, remove the lily to the cellar, where it must be kept cool and moist until spring.
Tropicals will not survive heavy frost and are considered annuals. In semitropical climates, cover the pool with plastic on frosty nights. Contrary to all expected norms in horticulture, the tropical lotus flower (not a lily, but a true water plant) is hardy even as far north as central Maine.
Planting. To plant waterlilies you will need a container, 11 or more quarts of heavy topsoil, 2 fertilizer tabs, and pea gravel.
Fill the container one-third full and add fertilizer tabs. Fill one-half full and position lily in pot. Gently add soil around the roots and tamp down. Keep the growing crown free of soil. Thoroughly saturate with water. Finally, top off the soil with a one-half-inch layer of pea gravel, again keeping the crown free. Lower the potted lily into the pool so that between 6 and 18 inches of water covers the crown.
Lilies require 2 to 3 weeks of adjustment before new growth resumes.
In Great Britain and Ireland, gardeners can buy all their waterlily needs from the local garden center. As yet, mail-order suppliers are the only source for equipment and plants here in the US. The largest is Lilypons Water Gardens, 6800 Lilypons Road, PO Box 10, Lilypons, Md. 21717. A major West Coast supplier is Van Ness Water Gardens, 2460 North Euclid Avenue, Upland, Calif. 91786.
For the names of other suppliers, write to: Water Lily Society, PO Box 104, Lilypons, Md. 21717. Anyone wishing to join the society is welcome. The requirements are not that you already grow waterlilies, but that you would like to start.