With the gardening season now in full swing, it is interesting to look at some of the specialized forms of gardening that have been gaining popularity. One of these is the water garden. Water lilies are a flower that is loved by many, but grown by few. The specialized conditions it needs are not difficult, and properly grown water lilies will flower well all summer once they are established.
Large pools with fountains and recirculating water are impressive, but the beginner might be better to start growing water lilies with a small pool or a large tub set into the ground with the top level with the soil surface. The edge of a tub or large container may easily be hidden with rocks or small plants. Larger, ready-made pools are also available made of fiberglass or plastic liners to set into the soil. They must be set properly on sand or damage to them may result in leakage. Large pools should be built by professionals.
Water gardens are essentially gardens that need bright sunlight and should be positioned where they will receive at least 5 hours of full sunlight each day. Some water plants will survive with less direct sunlight, but those that flower, such as water lily, will flower poorly or not at all as the amount of light decreases. Given more than 5 hours of bright light they will flower even better.
Water lilies develop best in quiet water warmed by the sun. There are two basic groups of water lilies: hardy water lilies and tropical water lilies. Hardy water lilies are best suited for our climate and may be left in the pool all winter if it is deep enough so it does not freeze completely. Tropical water lilies are not hardy and must be removed every fall and stored indoors in moist conditions for the winter. They should not be planted until water in a pool is quite warm. Tropical water lilies are often larger and more spectacular than the hardy types and also come in lavender and purple shades which are not available in the hardy types. Hardy water lilies are day blooming and most flowers close during the afternoon. Many tropical varieties are evening and night blooming which is a benefit for home gardeners that work during the day and view the pool more frequently in evenings.
Do not crowd water lilies. If the pool or tub is small, use dwarf varieties or plant only one. Crowding these plants not only reduces the number of blooms, but abundant leaves may entirely cover the surface of the water. Some water must be exposed, not only because it makes the pool more attractive, but fish kept in the pool will get better air exchange and also be able to catch insects on the open water surface. If excessive foliage develops, it should be cut out to maintain open water. When cleaning, always remove the older leaves as well as old flower stems.
Hardy water lilies may be planted now or anytime in May while the tropical ones should not be planted until early June unless the season has been very warm. Do not plant water lilies directly on the bottom of the pool. This makes them more difficult to maintain. They should be planted into large clay pots or wooden tubs or containers that are then placed into the pool. For dwarf varieties a container 9 to 10 inches in diameter is adequate but for large varieties, a container that holds about one bushel of soil should be used.
Handle the roots and rhizome carefully since many are quite brittle. After the rhizome has been planted, the container should be placed into the pool so that the crown of dwarf types is at least 5 inches below the surface of the water. The crown of large varieties should be 10 to 12 inches below the water surface. Bricks or blocks may be placed beneath a container to position it properly, as well as allow some water to flow entirely around the soil mass. Pool depth for water lily pools should be a minimum of 12 inches up to 24 inches.
These plants grow well in fairly heavy clay soils low in organic matter. Special fertilizer for water lilies may be purchased from nurseries or garden centers that specialize in the plants. Fertilizer should be mixed into the soil before placing the plants into the pool in spring. These are slowly available materials that are not quickly released in water.
During October the tropical varieties, as well as hardy types in small pools, should be removed. During the winter they should be kept cool but never subjected to freezing temperatures. Moisture must be retained around the roots by slipping a plastic bag around the plant and the container during storage. Check periodically since rot development is always a possibility, particularly for tropicals that might get too cool. Replant and set them back into the pool each spring.