Tips from the Plant Prop Shop: Propagation of Water Garden Plants: The Waterlilies

Incorporating a water garden into your landscape provides many benefits including enhanced aesthetic appeal and interest generated by the colorful and unique aquatic plants which create a focal point in any garden. Likewise, inclusion of a waterfall feature provides the soothing sound of cascading water resulting in feelings of harmony and relaxation. The water gardens at Wilmot Botanical Gardens provide these benefits to its visitors (Fig. 1). For many gardeners, the co-culture of colorful fish with vibrant aquatic plants offers the opportunity to learn about the aquatic ecosystem.

Fig. 1 – The water garden features provide unique landscape focal points within Wilmot Botanical Gardens.

Probably, the most recognized water garden plants are the waterlily (Nymphaea) hybrids (Fig. 2A,C,D). These plants consist of floating leaves attached to underground stems by elongated petioles. There are two types of waterlilies, the hardy and tropical waterlilies, of which there are many hybrids differing in flower color, leaf shape and pigmentation. Hardy waterlily hybrids were generated by hybridizing wild parental lines from European and North American. Hardy waterlilies are characterized by: 1) having the capacity to overwinter outside in a dormant state in colder climates; 2) producing lightly fragrant flowers which float on the surface (Fig. 2A); 2) not having night-blooming varieties; and 3) vegetatively reproducing via rhizomes, horizontally growing underground stems (Figure 2B). Hardy water lily flowers typically last for about 3-4 days. Both hardy and tropical varieties can be propagated sexually by seed but the seedlings produced won’t be true to type.

Figure 2. Waterlily types. A. Hardy waterlilies, like Nymphaea x “Attraction”, are adapted to tolerate lower temperatures and typically produce blooms which float on the surface. B. Hardy waterlilies vegetatively reproduce from horizontally growing underground stems called rhizomes. C. Day-blooming tropical waterlilies such as Nymphaea x ”Dauben” produce fragrant flowers which project above the water surface. D. Night-blooming Nymphaea x “Antares” has distinctly raised veins on the leaf underside. Depending on variety, tropical waterlilies can be propagated sexually by seed or clonally by tuber or epiphyllous plantlet production (see Figure 4).

Tropical waterlily hybrids are bred from native lilies from South America, Africa, South-east Asia, and Australia. These waterlilies are characterized by: 1) being prone to damage in water temperatures below 45°F; 2) producing profuse highly fragrant blooms in a wide color range that are projected above the surface; 3) being available in both day (Fig. 2C) and night-blooming (Fig. 2D) varieties; 4) having varieties with large leaves that are purple mottled and deeply veined on the underside; and 5) being vegetatively propagated from tubers, modified swollen stems functioning as underground storage organs (Fig. 3A).

Gardeners should consider incorporating a water garden in their landscape. In Florida, Lowe’s occasionally offers water garden plants, including waterlily rhizomes or tubers for $10.99. However, for more desirable varieties, the cost of purchasing a waterlily plant can range from $30 to $90 retail. There are many online sellers of water garden plants and supplies. Amazon is a great place to start! These initial costs should not deter you from creating your own water garden. While your first purchase may be expensive, both tropical and hardy varieties can be readily propagated to share with your friends!

Figure 3. Tropical waterlily propagation by tuber formation. A) Plants produce modified stem storage organs called tubers which can be separated and repotted into fresh soil. The tubers shown have sprouted producing new shoots and roots. B) Pots are first weighed down with bagged sand to prevent pots from floating or upsetting. C) Tubers are planted in pots partially filled with rich garden soil. D & E) Soil is covered with a 2-inch sand layer to prevent soil from dispersing into the water. F) Potted tubers are placed submerged to a depth allowing at least 6 inches above the top of the pots. Plants should receive at least 4 – 6 hours sunlight per day and be fertilized at 4 – 6 weeks intervals

A tropical waterlily can produce as many as 60 tubers per container in a growing season. These tubers should be harvested (Fig. 3A) in early fall before lower water temperatures cause tissue chill damage.  Tubers should be stored in moist sand at about 55° F until early spring. Each pot, used for transplanting, should first be weighted down with a small paper bag containing builders’ sand to prevent the pot from floating and tipping over as the plant grows (Fig. 3B). This occurs because waterlilies produce root systems with extensive air spaces making them very buoyant. Sprouted tubers can be planted into a 3:1 mixture of garden soil and composed cow manure. However, contrary to belief, I have observed that many varieties grow well in commercial potting mixes (Fig. 3C). The soil is covered with a 2-inch-deep layer of sand to keep the soil from floating out of the pot when submerged (Fig. 3D-E).  Potted tubers are submerged so that the top of the pot is at least 6-inches below the surface in an area that will receive from 4-6 hours sunlight daily (Fig. 3F). Aquatic plant fertilizer tablets are desirable as they can be pushed under the sand layer to allow controlled release of nutrients in the root zone.

Figure 4. Tropical waterlily propagation by epiphyllous plantlet production. A) Initial plantlet develops at the attachment point of the petiole and blade (arrow). B) Young plantlet with first leaf primordia developed. C) Leaf blade expansion continues during plantlet development. D) Mature plant development with basal rooting. This plantlet can be now transplanted into a pot.

A fascinating example of clonal propagation is the formation of so-called “viviparous” plantlets on the floating leaves of some tropical water lilies varieties (Fig. 4). Plantlets develops at the petiole attachment point with the blade (arrow Fig. 4A). The plantlets develop into mature rooted plants (Fig. 4B-D) and may flower while still attached to the mother plant. Plants can be removed from the parent leaf and established in their own pot. A single plant may produce many plantlets during the growing season. Treatment of the plantlets with plant growth regulators can greatly increase plantlet development (Kane et. al., 1991).

Hardy water lilies in north central Florida can be readily propagated by dividing and replanting the rhizomes produced after the first growing season in the following spring (Fig. 5A). In some varieties rhizomes grow linearly while others are highly branched clusters such as illustrated in Fig. 5B. A branched rhizome is removed from its container, the soil is rinsed off and the roots are then trimmed back (Fig. 5B). Typically, 8-10 leafy rhizome divisions can be harvested from one rhizome (Fig. 5C). These propagules are planted in containers as described for tropical waterlilies.

Figure 5. Hardy waterlily propagation. A) Nymphaea x “Gloriosa” with multiple rooted lateral rhizome clusters produced on a single rhizome after one growing season. B) Rinsed rhizome clusters prior to division. C) Eight lateral rhizome propagules harvested from a single rhizome. D) Individual rhizome propagule potted using method as described for tropical waterlilies in Fig. 3.

Many of the fascinating aspects of water gardening can’t be covered in a short article. Creating a water garden and learning how to maintain the interesting plants, especially the waterlilies, can be a rewarding endeavor. Don’t be afraid to get your feet wet!


Kane, M.E., N.L. Philman and D. Clayton.  1991. A technique for enhanced propagation of viviparous tropical water lilies.  Proceedings Florida State Horticultural Society 103: 319-322.

Michael Kane, Professor Emeritus

Environmental Horticulture Department, University of Florida