Growing water lilies in a bowl, known as tub gardening, allows you to bring the beauty of these aquatic plants to small outdoor spaces. This method is ideal for patios, balconies, or decks where a full-sized pond is not feasible. The process transforms a simple, watertight container into a miniature aquatic ecosystem. With the correct selection of plant and container, a stunning floral display can be maintained throughout the summer.
Selecting the Right Variety and Container
The success of a bowl water garden depends on selecting a variety specifically bred for confined spaces. Full-sized Nymphaea cultivars will quickly outgrow a container, but miniature or pygmy varieties thrive in the limited root zone. Look for dwarf hardy types like Nymphaea tetragona variants, ‘Helvola’ (yellow), or ‘Perry Baby Red’ (red).
The container must be watertight and non-draining, such as a ceramic bowl or a plastic tub. A minimum size for a single miniature lily is a container at least 12 inches in diameter, allowing space for the lily pads to spread. The vessel should hold enough water to cover the potted plant by 8 to 12 inches, providing the necessary thermal buffer and growing depth.
Water lilies require heavy garden soil, loam, or a clay-based mixture to anchor their roots. Avoid any mixes containing lightweight materials like peat moss, perlite, or vermiculite. These buoyant components will cloud the water and escape the pot.
The Planting Process
The water lily is first planted into a smaller, separate container before being submerged into the decorative bowl. A wide, shallow pot, about 6 to 10 inches deep and 12 to 18 inches wide, is ideal for the rhizome’s spreading nature. If the planting pot has drainage holes, line the bottom with burlap or newspaper to keep the heavy soil contained.
Fill the container about two-thirds full with the prepared heavy soil mixture. If planting a hardy water lily rhizome, position it near one edge of the pot at a 45-degree angle, with the cut end facing down. The growing tip, often called the “eye,” must be left uncovered and pointing toward the pot’s center so new growth can emerge.
Once the rhizome is secured, fill the rest of the pot with soil, leaving about an inch of space at the rim. Press a half-inch layer of clean, non-floating gravel or coarse sand over the exposed soil surface. This layer seals the planting medium, preventing fine particles from escaping and muddying the water in the decorative bowl.
The potted lily is then ready to be placed into the final display bowl, which should already be filled partway with water. Lower the planted container slowly and at a slight angle to allow any trapped air bubbles to escape without disturbing the soil. The water surface should settle between 6 and 12 inches above the soil line of the lily’s pot, ensuring the pads can reach the surface.
Daily and Weekly Care Requirements
Water lilies require a minimum of six hours of direct sunlight each day to produce blooms. Placing the bowl in a location that receives full sun from late morning into the afternoon will maximize flowering. Insufficient light will result in few or no flowers, even if the plant appears otherwise healthy.
Routine water management focuses on replacing water lost to evaporation, which can be significant in a small, sunny container. Top off the bowl with fresh water as needed to maintain the consistent depth above the soil, preventing the leaves and rhizome from drying out. Use a gentle stream of water to avoid splashing the gravel and clouding the water.
Water lilies will deplete the nutrients in their soil over the growing season. They benefit from regular fertilization using aquatic fertilizer tabs, which are formulated not to dissolve into the water column. These tablets, often with a balanced NPK ratio like 10-14-8, should be inserted deep into the soil every four to six weeks during the active growing period, from spring through late summer.
Push the tabs into the soil a few inches away from the plant’s crown or rhizome to prevent chemical burn, then cover the insertion point with gravel. Routine maintenance involves removing spent flowers and any yellowing or decaying leaves. Trimming this dead foliage close to the base of the plant directs the lily’s energy toward producing new growth and flowers.
Managing Common Issues and Winterizing
Container water gardens can experience a few common challenges. Green water, caused by microscopic suspended algae, is a frequent issue, especially in newly established bowls with high nutrient levels and warm temperatures. Partial water changes can temporarily reduce the algae population, but introducing aquatic snails, which graze on the algae, can help maintain clarity.
Aphids can sometimes infest the floating lily pads, clustering on the undersides or around the flower buds. These pests are easily dislodged by spraying them with a strong, focused stream of water from a garden hose, knocking them into the water where they drown or are consumed by other organisms. Over-fertilization can also contribute to excessive algae growth.
Preparing a hardy water lily for winter is necessary in climates where the water in the bowl will freeze solid. Stop all fertilization in late summer to encourage the plant to enter dormancy. Once the foliage has died back after the first few hard frosts, cut all the remaining leaves and stems down to the soil line.
If your bowl cannot be lowered into a deep pond, the potted lily should be moved to a cool, dark location that stays above freezing. This location, such as an unheated basement or garage, should maintain temperatures between 30 and 50 degrees Fahrenheit. Place the pot into a larger tub and cover the soil with a few inches of water to prevent the rhizome from drying out.