Water supports a surprising diversity of flowering plants, but “growing in water” describes several distinct habitats. Some plants are fully aquatic, requiring total submersion or floating on the surface of a pond or lake. Other species thrive in the saturated, shallow edges of water bodies, known as marginal areas or bog gardens. A third method involves cultivating non-aquatic plants indoors, rooting and growing them hydroponically in vases and jars.
True Aquatic Flowering Plants
True aquatic flowering plants live fully within a water column, either rooted in the substrate or floating freely on the surface. They provide shade and shelter for aquatic life in ponds and slow-moving waterways. The Water Lily (Nymphaea) is a prime example, with large pads resting on the water and blooms floating just above the surface. Hardy varieties survive freezing winters, while tropical types need warmer climates.
The Lotus (Nelumbo) is often confused with the Water Lily, but its flowers and foliage rise dramatically on stiff stems well above the water line, sometimes reaching three to five feet. Both deep-water plants must be potted in heavy loam or clay-type soil at the bottom of the pond, as standard potting mix would float away. They require full sun exposure to produce striking blooms and thrive best in water with minimal movement.
Floating varieties like Water Hyacinth (Eichhornia) and Water Lettuce (Pistia) are not rooted in the substrate and drift on the surface. These plants have showy flowers and help filter the water, but they spread rapidly and may require regular thinning to prevent them from blocking light.
Marsh and Marginal Bloomers
Marsh and marginal bloomers thrive where the soil is consistently saturated or covered by only a few inches of water. Unlike true aquatics, the plant’s crown must remain above the water line to prevent rot. They are often planted on the shallow shelves of a pond or in a bog garden, where their roots access constant moisture. These plants help filter the water naturally.
The Calla Lily (Zantedeschia aethiopica) is a popular marginal bloomer, known for its elegant, trumpet-shaped white spathes. This plant thrives at the pond’s edge where the soil is wet and its crown is kept above the water.
The Marsh Marigold (Caltha palustris) produces golden-yellow, buttercup-like flowers early in the spring. This perennial requires constantly moist or waterlogged soil, growing well in two to five inches of standing water. Certain Irises, such as the Japanese or Louisiana varieties, are also suited to these environments, preferring shallow water up to about eight inches deep.
Propagating and Growing Flowers in Water Indoors
Growing flowers in water indoors uses hydroponic techniques to cultivate plants that are not naturally aquatic. This method is often used for rooting cuttings, but some non-aquatic plants can be maintained in water indefinitely. Flowering houseplants like Begonias, Coleus, and Impatiens are good candidates. To start, a healthy cutting is taken just below a leaf node, the point where new roots are most likely to emerge.
The cutting is placed in a vessel of fresh, non-chlorinated water, ensuring lower leaves are removed to prevent rotting. Roots typically form within a few weeks. The water must be changed every one to two weeks to keep it clean and oxygenated. Since water lacks soil nutrients, long-term plants benefit from a monthly application of a liquid houseplant or hydroponic fertilizer.