Visitors gather around the lily pools in front of the Linnean House in the late 19th Century. The pool was located in what is now the Gladney Rose Garden. From the Missouri Botanical Garden Archives.

125 years ago, 30,000 people gathered at the Missouri Botanical Garden. They had come to see the bloom of the very first Victoria water lily flower. That was in 1894, and that is the last time that the lily pools were heated.

Water temperature is crucial to the health of the water lilies; they are native to the river systems of South America. They need heat to grow and can’t be transplanted from the Garden’s greenhouse to the pools until it’s late enough in the springtime that the water has warmed naturally. The dark water in the reflective pools helps to speed up the process–dyeing them black helps the pools to absorb the heat of the sun and warm the water more quickly. 

But now, for the first time since that first lily bloomed, one of the lily pools is heated. Thanks to a generous donation from Michael and Jeannie Gleason, the center pool of the Garden’s Central Axis got a new heating system in 2018. And it’s making a big difference. 

The Victoria water lilies are transplanted from the greenhouse to the reflecting pools, where they can grow to their full potential. Pictured: At left, Nursery Senior Manager Derek Lyle; at right, Senior Digital Media Specialist Cassidy Moody. Photo by Tom Incrocci.

How Big Did the Water Lilies Grow with the New Heating System?

The heat is a game changer in the race to grow the biggest Victoria lily pad. Since the pools were heated, the water lilies could be transplanted outside much earlier in the season instead of waiting for the spring sunshine to do all the work. A longer growing season means more time to grow, and that’s exactly what Nursery Senior Manager Derek Lyle wants to see. “As always, I hope for the largest Victoria ever!” he says. “I hope and pray the weather cooperates and there are no mechanical issues with the pool and heating system. Each year is completely different than the year before–the Victorias are very weather dependent.” 

The Central Axis reflecting pools, under construction and freshly completed in 1917. Heating elements were not installed in the pools until 2018; 101 years later. Photos from the Missouri Botanical Garden Archives.

And 2019 was the best year yet for lily pad growth: the Garden grew its biggest lily pad ever at 91 inches across. That’s over a foot larger than the typical growth of a Victoria in St. Louis, and just two inches short of the world record.

In 2019, the Garden grew its biggest lily pad ever at 91 inches across.

The Victorias’ performance this year is especially impressive considering the cool, wet weather that dominated spring and much of early summer. “The abundance of rain this spring was an absolute challenge,” says Lyle. “Lack of sunlight and constant downpours slowed the Victorias early on. During one morning in mid-July, we received more than 3” of rain at the Garden within a couple hours. This amount of rain cooled the pool at a rapid pace, causing the Victorias to stall and go into shock. From there on, their vegetative growth began to decrease.” But the 91 inch lily pad broke the Garden’s record nonetheless. This success can be traced in part to the new heating system and begs the question what the possibilities might be in a year when the weather cooperates. 

The Victoria pad in the foreground is the record-breaking 91 inch Longwood hybrid. Photo by Derek Lyle.

Can the Garden beat the World Record?

Beating our own personal record is worthy of a celebration. Lyle has a bigger goal in mind for next year, though. He’s setting out to beat the world record—and he isn’t far off. The largest Victoria pad ever officially recorded was just achieved this year in Gainesville, Florida. It was a Victoria cruziana measuring 93 inches across. Our 91 inch pad was a cross of the Victoria cruziana and Victoria amazonica. This variety, known as the Longwood hybrid, has the advantage of the amazonica’s massive size and the cruziana’s greater adaptability to outdoor pools. 

The competition for the biggest lily pad is fierce. “There are claims there was a world record set in Peru at 116 inches across, but it has not been entirely confirmed,” Lyle says, “and Victoria amazonica is known to grow up to 10’ across in its natural habitat, but no known data on record size has been established yet.” So, as it stands, our 91 inch pad is just two inches shy of the 93 inch record for the largest Victoria.

Horticulture staff measures the width of a Victoria water lily. This particular pad measured 6 feet 9 inches. Photo by Tom Incrocci.

And Lyle has plans to take it a step further. “This year, the Victorias were so large that they were growing out of the water,” Lyle says. That means they likely would have gotten bigger if they’d had the room to grow. “Victorias are dependent on the water depth as it indicates the difference between the rainy seasons. Once the water recedes (or the plant’s crown is out of the water), the Victoria immediately shuts down vegetatively and begins flower initiations.” If the water was deeper, the Victorias would have the space to grow to their full potential. So next year, Lyle plans to increase the depth of the pool by making the overflow pipe two inches taller. That’s the maximum depth that the pool can reach without overflowing into the surrounding flower beds. Those two inches ought to make a significant difference. It’s entirely possible that the record could be ours—we’ll just have to see whether the weather cooperates. 

A Victoria bloom. Once the water recedes (or the plant outgrows the water), the Victoria shuts down vegetatively and begins flower initiations. Photo by Kent Burgess.

Water Lilies in the Spotlight 

In 2020, the Garden’s water lilies will be highlighted in several displays around the Garden. Bayer Hall (on the second story of the Ridgway Visitor Center) will feature a photography exhibit of water lilies throughout the Garden, Butterfly House, and Shaw Nature Reserve; Nymphs of the Garden, an interdisciplinary exhibit on water lilies in science, art, and history, will open at the Stephen and Peter Sachs Museum on April 17, 2020; and Lyle plans to have a special exhibit on Nymphaeaceae species in the Swift Vista pools in front of the Linnean House. The display will feature only Nymphaeaceae species that occur naturally–no hybrid cultivars. “We have not had only species displayed in a pool in over 115 years here at the Garden,” Lyle says. The water lilies have been with us for well over a century, and next season will be their time to shine. If all goes well next year, we just might be able to add a world record to their story.

Kristina Schall DeYong–Digital Media Specialist