Water lilies are popular aquatic plants, celebrated for their striking beauty and the serene atmosphere they bring to ponds. Their large, floating leaves and vibrant flowers create a captivating display. Many gardeners wonder if these elegant plants will return year after year.
Perennial Nature of Water Lilies
A perennial plant lives for more than two years, returning to grow and flower season after season. For water lilies, their perennial status depends on their type: hardy or tropical. Hardy water lilies are perennials in most temperate climates, regrowing each spring. Tropical water lilies are not reliably perennial in regions with freezing winters and are often treated as annuals.
Hardy types possess rhizomes that store energy, allowing them to survive cold temperatures and re-emerge. Tropical water lilies form tubers sensitive to cold, perishing if exposed to freezing conditions. This difference in root structures dictates their ability to overwinter naturally.
Hardy Water Lilies and Their Return
Hardy water lilies are reliable perennials in USDA Zones 4 through 11, able to withstand cold winters. They survive by entering dormancy when water temperatures drop below 45-50°F (7-10°C). During this time, foliage dies back, and the plant’s energy is stored within its submerged rhizome, allowing it to endure freezing.
To ensure their return, plant hardy water lilies at the correct depth, typically with the crown 6 to 18 inches below the water’s surface. In colder climates where ponds might freeze solid, place potted lilies in the deepest part of the pond (2 to 3 feet deep) to protect the rhizome from prolonged freezing. Once spring arrives and water temperatures rise, the dormant rhizome sprouts new leaves and flowers.
Managing Tropical Water Lilies
Tropical water lilies are not reliably perennial in climates with freezing winters. These heat-loving plants thrive in warm water temperatures (above 70°F / 21°C) and are susceptible to cold damage. In regions where winter temperatures drop below freezing, tropical water lilies are often cultivated as annuals.
To preserve them in cooler climates, overwinter them indoors. This involves lifting the plant before the first hard frost, trimming foliage, and storing the tuber in a slightly damp medium like sand or peat moss in a cool, dark location. Alternatively, keep the potted plant in water indoors with sufficient light and warmth. In tropical and subtropical regions, where water temperatures remain consistently warm, these water lilies behave as perennials, continuously growing and blooming.
Essential Water Lily Care
Consistent care helps both hardy and tropical water lilies flourish throughout the growing season. They require ample sunlight for abundant blooms, ideally receiving at least 6 hours of direct sun daily. Proper planting depth is important; the top of the planting medium should be 6 to 18 inches below the water’s surface.
Regular fertilization promotes vigorous growth and flowering. Aquatic plant fertilizer tablets can be inserted into the soil around the roots every 3 to 4 weeks during the active growing season. Routine maintenance, such as removing spent flowers and yellowing leaves, also contributes to the plant’s overall health and encourages continuous blooming. These practices ensure hardy varieties return robustly and tropical varieties perform their best during their active period.