Waterlilies (Nymphaea spp.) expand the gardening space from land and air with bedded plants and climbing vines to aquatic areas such as ponds. Waterlilies are tropical plants, so choose waterlilies for your landscape only if you live in the appropriate warm climate. Waterlilies are a high-maintenance plant that can add foreign-inspired interest to your garden.
Waterlilies are plants that, as named, float in water. These lilies display fragrant geometric, upward-cupped flowers with green foliage referred to as "pads" that resemble a single leaf. Blossoms are generally available in white and tints of every color of the spectrum. Flowers grow up to a height of 1 foot with a width of 4 feet. Leaves may reach a length of up to 1 foot, according to the University of Florida Cooperative Extension Service.
Waterlilies are categorized into hardy waterlilies and tropical waterlilies. Hardy varieties are creeping plants with solid green whorled leaves. The flowers of hardy varieties display blooms with a citruslike fragrance in nearly every color of the spectrum except blue. Tropical waterlilies are clumping plants with jagged edges and splotched green leaves. Tropical varieties are available as day- or night-flowering plants with heavily fragrant blooms in hues of white, pinks and blues, according to the University of Minnesota Extension.
Waterlilies are available in a wide array of varieties. Some hardy varieties include Fabiola, a pink flower; Sioux, a yellow flower that becomes orange; and Colorado, a waterlily with a flower in a tint of peach. Tropical varieties include Director T. Moore, a dark violet flower that opens during the day; Aquarius, a blue-violet flower that opens during the day; and Missouri, a white flower that opens during the nighttime hours, according to the University of Minnesota Extension.
Keep waterlilies in 18 to 36 inches of water for successful growth. These tropical plants thrive in full sunlight. Most significant is the waterlily's need for food and grooming. Feed waterlilies through pellets or fertilizer spikes (available at aquatic stores) to satisfy the high food needs of the lily. Additionally, prune your waterlilies by deadheading flowers and cutting dead or injured plant parts back with a sharp knife; be mindful of your method as, with any plant, wounds may diminish lily health and leave your plants susceptible to pest infestation or disease, according to the University of Minnesota Extension.
Waterlilies are commonly attacked by pest infestation of black aphids and aquatic leaf beetles. Black aphids are small black insects that feed on plant tissue fluids, causing yellowing and deformation of leaves. For control, remove the aphids physically by washing them off of your water lilies with a hose; remove injured plant parts and transport affected plants into separate containers. Wash infested plants with insecticidal soap, and return to initial garden space when there is no longer the chance for soap to affect other plant or animal life. Aquatic leaf beetles are small visible grubs that chew holes in leaves and cause a spotted appearance. For control, remove grubs by hand, remove dead plant parts, rinse plants to remove eggs and, as with aphids, place in separate container for insecticide application for severe infestation, according to the Colorado State University Cooperative Extension. Always use biological methods before using chemicals.