Tropical Waterlilies and Merle Moore

In 1972 Gardens Director Merle Moore called me into his office announcing I could visit any botanic garden to learn procedures and improving our collection. I narrowed the choices and selected Missouri Botanical Garden (MBG), home of legendary tropical waterlily hybridizer George H. Pring.

I was so excited. I researched (with gracious help from Walter Pagels) everything he had written. I went to St. Louis in mid-summer and was blown away with the size and stature of their stunning waterlilies. MBG generously gave me tubers from their famed collection. This prompted us to develop more successful propagation facilities. We benefited enormously from an invaluable adviser, Patrick Nutt, a much loved and respected waterlily expert, hybridizer and horticulture manager at Longwood Gardens, Kennett Square, Pennsylvania USA. Patrick had trained under Pring. In addition to his ongoing benevolence to aspiring water gardeners, he kindly assumed a stewardship of the Pring waterlilies.

We continue to display outstanding Pring hybrids such as the pink Nymphaea ‘General Pershing’, blue N. ‘Marmorata’ and the stately white-flowering night bloomer N. ‘Missouri’. I cannot imagine these proven classics ever losing their prominence. As with the hardies, numerous high quality tropicals (including many new introductions) from other hybridizers exist.

At the Gardens we plant tropicals on or near June 10 and they flower through September. We use five- or seven-gallon (19- or 26-liter) squat containers for most plants. Our average water depth is 18-20 inches (46-51 centimeters). Starting with healthy plants is important. Midge larvae infest our tropical waterlilies as soon as we plant them, skeletonizing the leaves. Healthy plants soon recover. Night blooming tropical waterlilies offer a welcome addition to any water garden. For several years mallard ducks have destroyed our night bloomers (those with dark leaves are their favorite target) soon after planting.

Diverse tropical waterlilies sporting dazzling blue flowers, enthralling purple blooms, exotic pads, and nighttime blossoms, take over where hardy waterlilies leave. Star lilies with N. gracilis parentage are some of my favorites. The huge plants huge spread to 10 feet (3 meters) across with vibrant star-shaped blooms reaching up to 18 inches (46 centimeters) above the water surface. They are well suited to large pools

Tropicals continue to flower nicely on warm days through September as hardy waterlilies decline. After Labor Day (early September), hardies slow down noticeably. Many gardeners are not privy to the added beauty and relative ease of growing tropical waterlilies. Begin with healthy tropicals and plant them well after the threat of frost has passed. We plant ours one month after the average last frost day.

Our species collection has been enhanced thanks to the generosity of Kenneth Landon and Dr. John Wiersema.

Hardy Waterlilies

Denver Botanic Gardens and Colorado Water Garden Society hosted the third symposium of the International Waterlily and Water Gardening Society in 1987.

Enjoying a grand time with plenty of excitement, attendees scrutinized our hardy waterlily collection. I heard some cordial discussions . . . some just a bit testy.

“That’s Rose Arey!” said one. “Not so, it’s Rose Arey Hybrid!” exclaimed another. Who was right? Numerous similar disagreements abounded. I had some doubts earlier. I had more now. Dr. Kirk Strawn (as honest as they get) later suggested about half of the hardy waterlilies were labeled correctly.

I had labeled the waterlilies as they came from various nurseries. I later confirmed one waterlily sported three different names. Discussions and action followed, and a near miracle! IWLS and its early leaders (Norman Bennett, Ray Davies, Bill Heritage, Walter Pagels, Perry D. Slocum, Kirk Strawn, Phillip Swindells, Charles B. Thomas, etc.) proceeded to identify and rectify many errors that had crept into the trade. They created checklists and established registration procedures. The Gardens and other notable botanic gardens readily cooperated.

Perhaps the most significant contributions came from aquatic nurseries. The results were miraculous. Ten years later the Gardens displayed waterlilies for the thirteenth IWGS conference. Much of the earlier identification confusion had melded into agreement. A crushing hailstorm that unfortunately turned pads into confetti failed to dampen spirits. Within two weeks, the waterlilies were blooming profusely again.

Joseph Bory Latour-Marliac is renowned for his waterlily hybrids, many of which were painted by Claude Monet in his famous paintings. Allowing the bees to do the work, Latour-Marliac created a myriad of distinguished hybrids in yellow, pink, red, and white. Outstanding Marliac hybrid waterlilies we display in our pools include the vibrant red N. ‘Escarboucle’, stately white N. ‘Virginalis’, and wonderful, pink pastel N. ‘Amabilis’.

Pink N. ‘Anna Epple’ (Epple), shell pink N. ‘Rosy Morn’ (Johnson) and award-winning cup-shaped N. James Brydon’ (Dreer) show prominently in our pools.

Perry Slocum, Kirk Strawn, Kenneth Landon, Rich Sacher, Bruce and Brad McLane and many others have led a new era of remarkable hybridization for both hardy and tropical waterlilies.

Moving to the forefront now along with IWGS is Water Gardeners International (WGI) with its checklist of 1,800 waterlily names (each entry with vital data), registration guidelines, and Truly Named (internationally recognized waterlily certification program for correct labeling). I use the excellent checklist often and recommend its use to everyone interested in correct waterlily identification.

Rocky Mountain Legacy Collection

As many WGI/Victoria-Adventure readers know, eight outstanding new waterlily hybrids have been evaluated, named and introduced to the world by way of the Gardens’ Waterlily Trials. Major participants have included CWGS, IWGS, Bruce and Brad McLane (Florida Aquatic Nurseries [FAN]), Rolf and Anita Nelson (Nelson Water Gardens), Paul Stetson (Paradise Water Gardens), Kirk Strawn, Charles B. Thomas and Richard M. Koogle (Lilypons Water Gardens) and the Victoria Conservancy.

The tiny rose-colored N. ‘Attorney Elrod’ (Tomocik) persisted in our collection for over twenty years before receiving its name. The elegant soft pink N. ‘Denver’s Delight’ (Tomocik) has been grown in nearby Berkeley Park for over fifty-five years. Named by Gardens’ supporter Carol Purdy, it graces our pools in high numbers.

Growing during the season in a one-gallon (four-liter) container, N. ‘Cynthia Ann’ (Strawn) continuously produces delightful small peach flowers. Bruce McLane spotted this little gem in our pools and then FAN propagated it for the waterlily trade.

N. ‘Stan Skinger’ (FAN) is a small, darling, heavy flowering apricot tropical waterlily. The rich variegated leaves darken with age in our pools. When IWGS, the Gardens and CWGS combined to host the first Banksian Waterlily Trials at the Gardens in 1997, the vivid purple N. ‘William McLane’ (Florida Aquatic Nurseries) won the Banksian Award as best over-all new waterlily.

Nancy and Trey Styler (Victoria Conservancy) led the effort to formally register N. ‘Denver’s Delight’, N. ‘Stan Skinger’ and N. ‘William McLane’ with the IWLS Nymphaea Registrar.

Individually and as a group the aforementioned extraordinary waterlilies will long be celebrated, displayed and enjoyed by water gardeners across the globe!

They comprise the Rocky Mountain Legacy!

 Winter and Spring, Color and Activity

I am always thinking ahead to the next season, year or even several years. A surprising touch of color always welcomes visitors to our small but functional propagation facilities in greenhouse 3C. Here during all seasons we keep an assortment of vibrant tropical waterlilies in full flower.

Remarkably, the venerable purple tropical waterlily N. ‘Teri Dunn’ (Frase) flowered for 51 weeks last year in the Boettcher Conservatory. This feat is even more special considering the water temperature and sunlight are both much less during winter.

Design, budget and interpretation meetings too, are part of the off-season agenda. On the last Sunday of March the excellent volunteers of the Colorado Water Garden Society (CWGS, the world’s first water garden club) arrive to begin the process of preparing our summer displays. The volunteers are such of a boost their energy, joy and encouragement making things so much easier. It’s a bit apprehensive for me, realizing we are at the very start of potting and getting in place over three hundred waterlilies. Additionally, we display several hundred marginals in the pools every year.

The volunteers’ energy, joy and encouragement make things so much easier for me. Our aquatic displays would be minuscule without the CWGS volunteers!

As our pools fill in early April, here come the Canada geese, the bad guys. They do little decorating the walkways and waste no time dislodging and eating newly planted waterlilies and lotuses. Before lowering our hardy waterlilies ever so slowly into the pools, we secure them with bricks (kept off the lily crowns) to thwart the geese.

The first week of May presents us the optimal time to plant lotuses. We cover them with chicken wire cages to protect them from the geese, which we tactfully encourage to leave.

Special Attractions

Each summer the excitement throughout the Gardens and especially the water gardens is at a feverish pitch. And each year is a bit different with new surprises.

After a prolonged absence, several turtles appeared in our pools last year…and again this year. They were not friendly to the waterlilies in the Japanese Gardens pool, and disturbed the lotuses. This year they made the Monet Garden Pool their home again. In addition, they provided extra fun for those lucky enough to see them occasionally emerge above the water surface. Mallard ducks are perennial favorites as they nonchalantly glide from plant to plant.

Creating quite a stir this summer was the copper “Zen Doorway” sculpture placed in one of the Rose Garden pools. The rectangular doorway matched the formal lines of the nearby Reflection Pool. The “doorway” nicely framed the viviparous waterlilies or the artists at the opposite end of the pool. The reflections were captivating!   

Getting it Done!

Not to be forgotten are the many volunteers and supporters who help to make the water gardens a magical place each summer.

The volunteers of CWGS remarkably provide the labor, skill and enthusiasm each spring and fall in putting our gardens together and taking them apart. Coordinator Bill Powell is amazing and invaluable.

Nancy and Trey Styler (Victoria Conservancy) kindly provide us with Victoria waterlilies and are cherished supporters. They are invaluable, especially for their extended efforts with waterlily registration and the intern program.

Larry Knowles (Associates) is the long-time Wednesday irrigation technician. John Bayard with his dedication to the species waterlilies, carnivorous plants and lotuses is the ultimate team player. His contributions and importance are unsurpassed.

Volunteer icons and leaders on Sundays are Len and Doris Freestone. Their work with tropical waterlilies and gardens maintenance is very very special. Assisting them admirably this year have been Carla Mascarenas, Lynn Novitsky and Michael Chan.

The college interns have again provided a big boost with their energy, cheerfulness and energy.

Seasonal gardener Jermaine Brown has been a blessing. Thank you, Jermaine!

The inspiration and support of two-time world champion sprinter Allyson Felix is deeply appreciated.

Our relationship with the International Waterlily and Water Gardening Society continues with pleasure. The Gardens recently received a plaque honoring us for our contribution of classic hardy waterlilies used for the exhibition in the IWGS Annual Symposium at Suan Luang Rama 9 Park, Bangkok!

New this year is collaboration with Water Gardeners International and Victoria-Adventure (Kit Knotts). They are global leaders in disseminating water gardening information. We are truly excited about the enormous possibilities with WGI.

I recognize and appreciate the wonderful support of Director of Horticulture Sarada Krishnan, and all of the splendid people in Horticulture, Operations, Education, Interpretation, Records, and the entire Denver Botanic Gardens staff.

See you at poolside,
Joe T.