Water lilies, with their delicate blooms and broad, floating leaves, transform any water feature into a serene, captivating oasis. These aquatic plants add visual interest and natural elegance to ponds and water gardens, making them a popular choice for aquatic landscapes.
Water Lily Basics
Water lilies (Nymphaea) are celebrated aquatic plants characterized by their large, often fragrant flowers and flat, circular leaves that rest on the water’s surface. These captivating plants come in a diverse palette of colors, including white, pink, red, yellow, orange, and even shades of blue and purple. Their sizes vary, from miniature varieties suitable for small tubs to vigorous types that can spread several meters across a larger pond.
There are two primary categories: hardy and tropical water lilies. Hardy water lilies are perennials that survive winter dormancy in colder climates, growing from rhizomes, with flowers usually floating on the surface in white, yellow, pink, and red hues. Tropical water lilies are sensitive to cold, often grown as annuals or overwintered indoors. They offer a wider range of vibrant colors, including blues and purples, and their blooms are often held several inches above the water. Tropical varieties typically grow from tubers and can be more fragrant and prolific bloomers.
Planting Water Lilies
Successful planting begins with selecting the appropriate container, which is usually an aquatic basket with mesh sides. A large basket, typically 5 to 10 liters, is suitable for most water lilies, though dwarf varieties may thrive in smaller 2-liter baskets. Line the basket with burlap or newspaper to prevent the soil from escaping into the pond water.
Fill the container about two-thirds to three-quarters full with a heavy clay-based loam or specialized aquatic planting media, avoiding lightweight potting mixes that tend to float. For hardy water lilies, position the rhizome at a slight angle, with the cut end deeper in the soil and the growing tip pointing towards the center and slightly above the soil surface. Tropical water lilies, which grow from tubers, should be planted in the center of the pot with the growing point slightly raised. Firm the soil around the plant and add a layer of washed pea gravel or small river rocks on top to secure the soil.
After potting, slowly lower the planted container into the pond at an angle to allow trapped air to escape. Initially, place the pot so the crown is covered with about 15-25 cm (6-10 inches) of water, or shallower for young plants. As the plant grows and its leaves reach the surface, gradually lower the pot in stages until it rests at its final recommended depth, which can range from 30-60 cm (12-24 inches) depending on the variety. Spring and early summer are ideal times for planting, as the warmer water temperatures encourage establishment.
Caring for Water Lilies
Water lilies flourish in full sun, requiring at least six hours of direct sunlight daily to promote abundant flowering. Maintain optimal water depth for your specific lily variety; large water lilies may prefer depths around 75 cm, while smaller ones thrive in 20 cm of water. Adjusting the depth as the plant matures ensures proper light exposure and growth.
Water lilies are heavy feeders and benefit greatly from regular fertilization. Use aquatic fertilizer tablets, pressing them into the soil near the rhizome every two to four weeks during the growing season. This consistent nutrient supply supports vigorous growth and continuous blooming. Regular removal of spent flowers, known as deadheading, encourages the plant to produce more blooms. Promptly remove any yellowing or decaying leaves to maintain plant health and prevent nutrient competition.
Hardy varieties can often remain in the pond year-round in zones where the water does not freeze solid at the root level. If freezing is a concern, move the potted plant to the deepest part of the pond or store it in a cool, dark, frost-free location, ensuring the soil remains moist. Tropical water lilies, sensitive to cold, are typically treated as annuals or brought indoors before the first frost. They can be stored as dormant tubers in damp sand or peat in a cool, dark place, or maintained in an active state in a warm, well-lit environment.
Addressing Water Lily Challenges
One common issue in ponds is algae growth, which water lilies help mitigate by shading the water and competing for nutrients. If algae becomes excessive, adequate plant coverage can help maintain water clarity. Aphid infestations, appearing as small black, green, or brown insects clustered on leaves and stems, can occur. These sap-sucking pests can be managed by gently hosing them off the leaves or submerging the affected leaves for a day or two to drown them. Avoid using chemical pesticides, especially if fish are present, as they can harm aquatic life.
Lack of blooming is a frequent concern, often stemming from insufficient sunlight. Nutrient deficiencies are another cause; if leaves are small or blooms are sparse, regular fertilization with aquatic tabs may be needed. Overcrowding can also inhibit flowering, as plants compete for resources. If a water lily has outgrown its container or the leaves are standing significantly above the water, it may need repotting or division.
Yellowing leaves, beyond natural aging, can indicate a nutrient deficiency, particularly if the pond is newly established or has little accumulated sediment. Consistent fertilization often resolves this. Additionally, planting too deeply can prevent young lilies from receiving enough light, leading to poor growth and a lack of flowers. Adjusting the depth to the recommended range for the specific variety can help the plant thrive.