Tips for Cultivating and Maintaining Indoor Water Lilies

Jon VanZile has spent nearly ten years as a writer focused on houseplants and indoor gardening. As a seasoned professional, his work on plants and horticulture has been featured in various national and regional publications.

Water lilies comprise numerous species within the genus Nymphaea. These plants are found in many regions across the globe, with their origins traced back to South Africa, the northern hemisphere, and Australia. Despite the significant variations among the species, all water lilies are cherished for their stunning appearance. They generally feature broad, floating leaves and exquisite, frequently vibrant flowers.

Water lilies are stunning additions to ponds and expansive outdoor water features. Their beauty leads many to consider the possibility of cultivating them indoors for daily enjoyment. Although it is feasible to grow water lilies as houseplants, it presents a significant challenge. Even with optimal care, achieving blooms can be elusive. If you decide to pursue this, select the appropriate variety of water lily and be ready for the likelihood of frequent setbacks alongside occasional successes.

Is it possible to cultivate water lilies indoors?

Water lilies are typically categorized into two main types: tropical and hardy varieties. Tropical water lilies thrive in warm water and are known for their large, vibrant blooms. However, they are not ideal for indoor cultivation because of their size, specific temperature requirements, and the considerable space they require for optimal growth. In contrast, hardy water lilies are found in temperate climates, such as those in North America. While they are generally smaller than their tropical counterparts, the dwarf varieties are more appropriate for indoor water gardens, as they fit well in smaller containers.

Water lilies are among the most particular plants when it comes to indoor environments, which is why cultivating them indoors is typically reserved for passionate gardeners. Even the more resilient varieties are not ideal for those looking for low-maintenance decorative houseplants. To successfully grow either tropical or hardy water lilies indoors, it is essential to maintain precise water temperatures and quality, along with an ample supply of light. Nevertheless, the subsequent recommendations are primarily geared towards the indoor cultivation of hardy lilies.

Tips for Cultivating Water Lilies Indoors

Sunlight

For a water lily to have a chance of flourishing indoors, it requires a significant amount of sunlight—likely even more than you might expect. These plants thrive best when they receive a minimum of four to eight hours of direct, unfiltered sunlight each day.

Man-Made Illumination

If you don’t have the advantage of a sunroom or a heated greenhouse, the absence of natural sunlight in your home during the winter will likely require you to provide additional lighting to encourage your water lilies to flower. Position the grow lights directly over the plants and operate them for 12 to 18 hours daily to mimic the effect of eight hours of sunlight. You might need to try various light bulbs and fixtures to find the optimal lighting setup.

Heat and Moisture Levels

Ensure that the water temperature is suitable for the specific species of water lily you are cultivating. Tropical water lilies cannot survive in water temperatures below 60 degrees Fahrenheit, and they typically require temperatures above 70 degrees Fahrenheit for optimal growth and blooming. In contrast, hardy water lilies do not have strict temperature requirements. A temperature of 68 degrees Fahrenheit, which is typical for indoor winter conditions, is adequate for hardy water lilies, but it’s important to maintain a consistent temperature and avoid significant drops during the night.

If needed, think about incorporating a water heater for your aquarium to maintain optimal temperatures for the water lilies you are cultivating.

Watering

When the tank or container’s water level decreases, replenish it with spring water or distilled water that has been allowed to warm to room temperature. It’s best to ensure that the top of the growing basket is submerged by a minimum of 12 inches. If you need to use tap water, allow it to stand for a minimum of 24 hours to enable the chlorine to dissipate.

Fluid Movement in Water

An air bubbler, similar to those utilized in fish tanks, is an excellent addition to indoor water gardens. It helps to oxygenate the water, preventing stagnation and unpleasant odors. With proper aeration, the frequency of water changes can be reduced.

Fertilizer

To ensure optimal growth of water lilies, it’s beneficial to incorporate liquid fertilizer or fertilizer pellets specifically designed for aquatic plants into the water. Whenever you introduce more water into the tank, it’s advisable to also add a small quantity of fertilizer.

Trimming and Upkeep

Clear away any dead leaves as they show up to maintain fresh water and avoid stagnation. A significant downside to cultivating water lilies indoors is the odor associated with stagnant water, although cloudy water is unlikely to harm the plants. It’s perfectly fine to replace the water occasionally.

Vessel and Dimensions

Certain compact varieties of resilient water lilies can thrive in containers as small as 15 gallons, including medium-sized fish tanks or galvanized tubs. The water lilies are situated in a net pot or planting basket filled with a suitable growing medium. When growing indoors, it’s important that the basket is small enough to allow water to circulate freely around it, and short enough to keep the top of the basket submerged well beneath the water’s surface. For a variety of species, the water level should be maintained at least 12 inches above the top of the net pot that contains the plant.

Soil for Potted Plants and Water Drainage

Although water lilies thrive in water, they still require a suitable growing medium. An ideal approach is to use a plastic net pot or a planting basket, placing rocks at the bottom for stability, and then filling it with a growing medium like sand, perlite, or a specialized aquatic planting mix.

Planting and Transplanting Water Lilies

Once you have filled the net pot or planting basket with the appropriate growing medium, position the plant in the pot, ensuring that the growing tip remains slightly above the surface while the entire rhizome is submerged. Place the pot into the water container, allowing water to flow freely around it. After potting, your water lily should not need to be repotted; it is advisable to begin with a new plant when the water lily matures and outgrows its container.

Transplanting Indoor Water Lilies to an Outdoor Setting

Transferring water lilies that are cultivated as indoor plants to outdoor settings is generally not advisable. These plants, which are used to the stable environment of an indoor water tank, often struggle to adapt to the sudden changes in water temperature and chemistry that an outdoor pond presents. An exception might be if the entire indoor tank can be relocated to an outdoor patio during the warm summer months, but even in this scenario, the transition can be too stressful for the plants. Therefore, if you are nurturing water lilies indoors, it is wise to avoid the risk of moving them between environments.

Are water lilies and lotuses the same?

Water lilies and lotuses usually thrive in pond environments. Water lilies feature robust, waxy blooms and leaves with notched edges, while lotuses possess delicate, paper-like foliage.

What are the disadvantages of cultivating water lilies?

Water lilies that grow outdoors can create thick layers that can harm aquatic ecosystems. In contrast, indoor water lilies, similar to other houseplants, are susceptible to a variety of common pests such as aphids, mealybugs, scale insects, and whiteflies. Furthermore, cultivating tropical water lilies indoors can be challenging due to their significant space and care requirements, especially when compared to the more manageable indoor dwarf hardy water lilies.

Which types are most suitable for cultivation indoors?

Dwarf hardy water lilies are ideal for cultivation indoors. Notable varieties to consider are: ‘Aurora’, featuring orange-apricot blooms and thriving in water depths of 12 to 24 inches; ‘Denver’, which produces yellow flowers and can flourish in just 6 inches of water; ‘Fabiola’, showcasing bubblegum pink flowers and growing well in 6 to 10 inches of water; and ‘Hermine’, which has white flowers and can adapt to water depths of 6 to 24 inches.

Will my water lily flower in its first year?

When water lilies are cultivated from rhizomes under optimal conditions, they typically flower within their first year. However, it is quite common for the plant to face challenges for a year or two while the gardener adjusts the indoor environment to better suit its needs.

What are the best methods for wintering outdoor water lilies?

In regions with colder temperatures, you can successfully winterize hardy outdoor water lilies by taking the potted plant out of the pond, trimming the leaves, and placing it in a plastic container or bag. Store it in a cool basement or a heated garage, maintaining a temperature of around 50 degrees Fahrenheit throughout the winter to keep it in a dormant state. When you return the plant to the outdoor pond in late spring, it usually emerges from dormancy and starts to grow vigorously once more.