NYMPHAEA – Cultivation of Water Lily (Blue Lotus)
DESCRIPTION: This group is commonly known as Water Lilies. These are hardy and tropical, aquatic perennials native to Australia, South Africa and the Northern Hemisphere. There are many hybrids, which have been developed from the wild species. Water Lilies produce handsome, floating foliage and gorgeous blossoms.
There are four types of rootstock in the Nymphaea group. Water Lilies are potted and propagated according to the kinds of roots they have and these methods will be described below in their specific sections. Tuberosa rhizomes are thin, horizontal growths with rapidly growing eyes along their length. Leaves and flowers are produced along the rhizomes rather than from a specific growing tip or eye. Odorata rhizomes are thick, chunky, horizontal growths with eyes also growing along their lengths. The eyes will grow into thick branches if not trimmed off. Leaves and blossoms are produced from growing tips. Marliac-type rhizomes grow horizontally, but stay more together rather than creeping along as the others do. It is also grows less vigorously than the others. Mexicana types have upright growth. New tubers form either right under or along side the mother tuber, or are embedded within the tuber. Tropical Water Lilies and some hardy kinds grow from this type of root.
Tropical Water Lilies – Tropical Water Lilies usually hold their flowers above the surface of the water. There are day-blooming and night-blooming varieties. The flowers are open for 3 or 4 days each. They need a water temperature of 70º F., though established plants can survive a bit lower. The spread of tropical Water Lilies ranges from 3 to 12 feet. N. ‘Evelyn Randig’ is a gorgeous variety having large (14 or 15 inches), round, bright green leaves conspicuously blotched with purple. The flowers are dark raspberry pink with greenish based sepals veined with purple. The cup-shaped flowers grow 7 to 9 inches across. N. ‘Director George T. Moore’ has fragrant, dark violet-blue flowers that measure 7 to 10 inches across. The round leaves are lightly mottled with purple and grow 10 to 12 inches across. N. ‘Enchantment has pink flowers and large, bright green, oval leaves that have serrated, wavy margins. N. ‘Mrs. George H. Pring’ has white flowers striped with grayish-green. The ovate, green leaves are blotched with purple when young. Night-blooming Water Lilies open about dusk and close by noon the next day. The flowers last 3 or 4 days each. N. ‘Antares’ is a beautiful variety with dark red flowers and orange stamens. The cup-shaped flowers are 6 to 10 inches across. The green leaves have wavy borders and pointed projections. Young leaves are bronze veined with green.
Hardy Water Lilies – Hardy Water Lilies can be grown in cooler climates. As long as the rhizomes do not freeze, they will survive the winter. The spread of hardy Water Lilies ranges from 3 to 8 feet. They are available in many different hues and some are changeable, that is, they change color over their 3- to 4-day blooming period. Hardy Water Lilies don’t bloom as abundantly as Tropical Water Lilies and they don’t hold their flowers high over the water. Since these Water Lilies are hybrids, most are sterile and need to be reproduced by division or by rooting the “eyes” found along the rhizomes. These varieties will not thrive in very warm climates, as high temperatures will cause them to burn and wilt. N. ‘Peaches and Cream’ is a lovely variety having fragrant, pink outer petals and yellow inner petals that curve inward. Its round leaves are speckled with purple when new. N. ‘Darwin’ has large, green leaves and double flowers that resemble Peonies. The central petals are light pink darkening with age. The outer petals are white taking on a pinkish hue by the third day. This is a very handsome variety. N. ‘Perry’s Magnificent’ has dark dusty rose, stellate flowers with yellow centers. There is a conspicuous red spot in the middle of the yellow centers. N. ‘Almost Black’ is just that; the outer petals of these flowers are very dark red turning black toward the center. The blossoms are 8 to 9 inches across. N. xlaydekeri ‘Fulgens’ has cup-shaped flowers of bright burgundy with almost white outer petals. N. ‘Gonnere’ produces gorgeous, pure white flowers that are 4 to 6 inches across. N. ‘Solfatare’ is a changeable Water Lily. The inner petals start out a yellowish apricot, turn to a creamy peach and finally peach. The outer petals are darker shades. These cup-shaped flowers measure 3 or 4 inches across.
There are many other varieties of Water Lilies that will be mentioned below along with a brief description of their flower’s colors.
POTTING: When potting your Water Lilies, a little preparation is first necessary. If your rhizomes are not bare-root, trim off the roots, leaving only a few, new roots to help anchor and establish it, and cut leaf stems close to the rhizome. Trim the rhizomes so that they are only 2 or 3 inches in length. Throw away the oldest pieces that look dead and hollow. Any roots and foliage that is left attached should be covered with wet newspapers or damp towels to prevent them from drying out before they’re planted.
For tuberosa- and odorata-type rhizomes, plant in a large, strong container. Place one aquatic tab for every gallon of soil around the bottom and fill three-fourths of the pot with good topsoil enriched with bone meal. Mound the dampened soil and place the cut edge of the rhizome against the wall of the pot. Tilt the tubers at a 45-degree angle so the growing tip will be at soil level. If there are roots, spread them across the soil. Fill the rest of the space with soil, patting it to decrease air pockets. Make sure not to cover the growing tip. The pot can then be carefully lowered in the water.
For mexicana-type rhizomes and tropical Water Lilies, plant in the center of the container because they usually grow vertically rather than horizontally. They are planted the same way as the other tubers, except the crown of the plant should end up above soil surface. Tropical Water Lilies should not be set in the water until it maintains a 70º F. temperature or higher.
During the winter, hardy Water Lilies should be moved to the deepest, ice-free part of the pond. In regions where temperatures drop below -10º F., Water Lilies that have mexicana parents should be taken from the pond and stored, in their pots of soil, in airtight bags in a cool, non-freezing place. Make sure that they don’t dry out. Hardy Lilies that are cultivated in shallow ponds or tub gardens should be stored in the same way. You can also hose away the soil and wrap the rhizomes in living sphagnum moss. Put the wrapped plant in an airtight plastic bag and store in a cool, non-freezing place. Tropical Water Lilies can be left in the water only in tropical climates where temperatures stay above about 40º F. In colder zones, remove the Water Lilies from the pond before the first hard frost. They can be moved to a greenhouse pond with full exposure to the sun. They don’t need to be fertilized. Once the water outdoors has returned to a temperature of 70º F. or more, they may be placed back in the pond. Another method is to keep potted plants outdoors until the second frost and then hose away the soil from the tubers and air dry for two days. Remove any leftover soil and pieces of root while you remove small tubers from the mother. Store them in jars of distilled water at a 50º to 55º F. temperature. In the spring, dose them with an anti-bacterial, anti-viral and a fungicide before planting them in small pots about 4 weeks before the outdoor pond has maintained at least a 70º F. temperature. Grow them in a sunny location in warm water. Once the water temperature outdoors has warmed, they are repotted in larger containers and placed in the pond. The last method is started as the previous method, except the tubers are stored in airtight plastic bags filled with damp, not wet, sand. Store them in a cool, dark place at a 50º to 55º F. temperature.
PROPAGATION: As mentioned previously, in the description section, Water Lilies have four kinds of roots. They all produce growing “eyes” or growing points on the tubers. The mexicana rhizomes produce tubers like corms or bulbs at the base or even embedded within the mother plant.
Tropical Water Lilies – Day-blooming tropical Lilies may be placed in one-gallon or smaller containers and starved to produce overwinter tubers. “Starving” means feeding the plant when it’s planted and maybe the first month or so. A container with no holes should be used to prevent the roots from escaping and finding nourishment elsewhere. If you are pulling up the plant just before fall, take it from its pot, hose away the soil and check for tubers around the bottom of the mother tuber. Rinse them and store them in slightly damp sand or in distilled water at 50º or 60º F. for the winter. In the spring, plant your tubers in one-gallon containers with no drainage holes. They should be filled with loamy soil that is covered with about an inch of sand. The top of the upright tuber is set at the bottom level of the sand. If you don’t know which end is which, plant it on its side. Two or three crops of plants will be produced in one growing season. When the first crop has a couple of surface leaves, rinse away the soil and repot the small tubers in small pots submerged in shallow water. Another crop may be gathered during the season, or they can be left attached to the mother plant until you lift the plants in the fall. You might want to keep the small tubers attached because removing them weakens the mother tuber. The same methods of propagating are used for night-blooming Water Lilies, though the tubers are found embedded within the mother plant’s rhizome. Some tropical Water Lilies can be increased by viviparous reproduction. This is the development of tiny plants at the point of a leaf where the two lobes connect. Some varieties will produce plants from wilted flowers; however, this is rare. The small, viviparous plantlets develop tiny leaves and some roots, but don’t grow vigorously until the parent leaf begins to die. When you see roots growing, remove the new plant and pot them in small containers and treat as a seedling with 2 or 3 inches of water over the soil. Protect them from direct sun and begin feeding applications of fertilizer.
Hardy Water Lilies – When a Water Lily is divided in its second growing season, many of these growing points will be large enough to produce flowers. If the growing eyes have produced enough growth, they may be snapped free from the mother plant; otherwise, they may be cut off and potted in 4-inch pots and grown to flowering size.
Water Lilies may also be increased by sowing seeds. When a Water Lily blossom has been fertilized, the flower will retreat beneath the water’s surface in a coiling spiral after the normal blooming period of 3 or 4 days. Unfertilized flowers will just float downward in the water, their stems remaining straight. Seeds can be collected by placing muslin bags over the blossom as the seeds ripen or by gathering a fertilized pod about 10 days after its submersion to allow it to ripen in a container of distilled water. Once the seeds are released from their pods, they may be planted. If you plant fresh seeds, don’t remove the gelatin coating. Shallow seed pans or margarine tubs can be filled with good garden soil. Spread the jellied seeds or individual seeds evenly over the surface of the soil and lightly sprinkle sand to cover them; they are then gently watered. Place the containers in an aquarium or bowl of water with no more than 2 or 3 inches of water covering the soil’s surface. They need to be set in a warm, well-lighted spot. Strong, direct light, however, can damage or kill your little plants. After a few weeks, the first baby plants will sprout. Once the first leaves reach the surface of the water, the plants may be picked out in clumps, carefully washed clean of soil and pulled apart from each other with toothpicks. Plant them separately in small pots or margarine tubs with the soil used above and cover them with 2 to 4 inches of water over the soil’s surface. Bone meal and aquatic plant fertilizer should be incorporated in the bottom half of the container; monthly feedings aren’t necessary. It will probably take 6 months for the plants to grow large enough to plant outdoors. As the seedlings grow, check for growth of algae, which can quickly kill them. Carefully pick away the algae by twirling it around a toothpick. If algicide, even a diluted amount, is applied, it may kill the tender plants.