Read about Tamara Kilbane 


Water Gardening at Sarah P. Duke Gardens
Durham, North Carolina USA

A Look Back at 2008

by Tamara Kilbane, Horticulturist
Click images to enlarge 

It's that time of year again - winter has settled in, bringing with it shortened days, chilly weather, and empty ponds. While these months following the holidays have never been among my favorites, they do offer the opportunity to look back on past water gardening seasons here at Duke Gardens, which is always accompanied by eager anticipation for the busy months to come. Our waterlily team (consisting of faithful volunteers John Wyman, Karen Webbink, Jeff Prather, Jean Reniers, and me) stayed very busy over the last twelve months. Here are some highlights of our year.  

Jean Reniers, John Wyman, Jeff Prather ready Victoria for the pond 


The 2008 season began with the arrival of Victoria seeds from Kit Knotts and Dave Brigante in early February. Thanks to the help of volunteer Karen Webbink, who arrived each Thursday morning to help with fertilization, water changes, and record keeping, we had several healthy Victoria 'Longwood Hybrid' plants to add to our summer displays. Dave was also kind enough to send us bare-root plants of V. cruziana and V. 'Adventure' in the late spring to highlight our main display pond.

Also on order for the upcoming season were several lotus tubers, including the hybrids 'Sweetheart', 'Charles Thomas', 'Angel Wings', 'The President', 'Perry's Giant Sunburst', and 'Carolina Queen', along with the North American native species, Nelumbo lutea.

Nelumbo 'Charles Thomas'

The hybrids were planted in containers along the front entrance to our Visitor's Center and in several ponds throughout the Gardens, while the latter was added to a pond in our Blomquist Garden of Native Plants.

One of the highlights of each season is growing the new waterlily hybrids entered in the annual IWGS New Waterlily Competition. This year's contest brought in a higher number of entries which arrived in late spring. These were potted and placed in our heated greenhouse tubs until the pond water had warmed sufficiently to transfer them outdoors. June rolled around and we were set to go, with the contest lilies and our tropical aquatics making the transition to our outdoor display ponds with ease.

What followed was our first challenge of the season, an impressive algae bloom that covered one display pond with a bright green film. The black dye that we use annually in our ponds unfortunately did not prevent this persistent strain from gaining a foothold on the top few inches of the water's surface. It was eye-catching to say the least. A moment I will never forget from that week was when a young boy visiting the Gardens saw me wading through the pond and yelled, "Look mom, there's a lady in the swamp!" Not exactly the words you want to hear when you're tending to a display water garden, but I had to laugh.

Virtue Peace Pond
with algae bloom 

The addition of water lettuce (Pistia stratiotes) to the upper pool of this pond seemed to help with our algae problem, along with cooling temperatures and some much-needed rainfall. We did however make the decision to hold the waterlily competition in a different pond to err on the side of caution. This turned out to be a very positive change. The new location was in a central area of the Gardens where more visitors were able to view these brand new waterlilies. As a result, the voting turnout for the second annual People's Choice Awards doubled that of last year, with nearly 1,400 people casting ballots for their favorite lilies.

Interestingly, the public voting and the official voting by the panel of IWGS judges was nearly identical, with top honors in both going to the tropical waterlily 'Ultra Violet' from Florida Aquatic Nurseries and the hardy waterlily 'John Wedgwood' from hybridizer Andreas Protopapas. 'Ultra Violet' was also named the Best New Waterlily overall for 2008. It is always a pleasure to not only grow these beautiful new hybrids each year but also to see our visitors' enthusiastic responses to the plants. We even had a few people suggest possible names for the new hybrids.

Our visitors were also able to admire last year's winning waterlily, 'Suwanna', which again showed consistency in bloom color throughout the summer months outdoors. We did notice that the lavender shades tended to fade with age, as well as with more intense sunlight, which is not uncommon for tropicals. The petal variegation was more pronounced in the second plant of the hybrid that we kept indoors in our greenhouse.  

Nymphaea 'Suwanna' >

Nymphaea 'Ultra Violet'

Nymphaea 'John Wedgwood'


Fish and Wildlife

Besides the algae, the waterlily team had to battle the ever-present and none too respectful creatures whose love of aquatic plants rival our own, though for different reasons.  

  The season began with a battle with a small population of baby turtles that found the newly planted lilies to be tasty and irresistible treats. Plastic mesh was attached to the outer rim of each pot to ward off unwanted nibbling, though some babies went to great lengths (or in this case heights) to get a forbidden bite. A floating turtle trap was also added to the pond to capture these troublemakers and their larger parents, which were then transferred to a pond at the farthest reaches of the Gardens. 

The goldfish that call the pond waters home weren't going to let the turtles have all of the fun, so the next challenge became protecting the plants from being uprooted. The soil in each pot was topped with large stones, which kept the lilies anchored securely. Then came the mallard ducks with their babies, which seemed to take great pleasure in garnishing their daily diets with a side of waterlily blooms. This is a problem we seem to encounter each year, and any advice from other growers about how to deter water fowl would be welcome!

Towards the end of the summer, the two great blue herons that frequent the ponds throughout our 55 acre (22 hectare) Garden began to see a new potential in our Victoria waterlilies.

Great blue herons and
V. 'Longwood Hybrid'
Photo by  Karen Webbink
One afternoon as I sat beside the pool housing the competition lilies and two Victoria plants, one of the herons walked carefully around the perimeter of the pond, surveying the depths for small fish. As I watched in amazement, he paused beside the V. cruziana and, with a quick flap of wings, hopped carefully onto one of the larger leaves. Finding the pads to be ideal platforms to fish from, the following weeks were filled with sightings of each heron perched atop the Victorias in two of our ponds. Even more impressive, the leaves were never damaged in the process and held the birds' weight with ease. 

Unfortunately, not all of our Victoria plants remained undamaged throughout the summer months. The remnants of two tropical storms made their way through the Gardens, bringing heavy rainfall that resulted in flash flooding. Our largest Victoria 'Longwood Hybrid' nearly escaped its pond to head downstream, and unfortunately what little remained of the plant was completely destroyed by the second storm.  

Also taking a hit from the fierce weather were the new floating islands we had installed in a retention pond at the north end of the Gardens. Our experiment to see how these planted rafts could aid in the improvement of water quality was cut short when the force of the storm water sucked the islands into a drain at one end of the pond. We hope to renew the project next season, this time with a new and improved anchoring system! 

Fall and Winter

With the excitement of the season winding down, it was time to begin removing the tropicals from the outdoor pools to store them over-winter as tubers or small plants in the greenhouse. This is always a bittersweet time for us, as the summer months seem to fly by much too quickly. Other fall tasks included cutting back our hardy aquatics and moving our hardy waterlilies to deeper sections of the ponds where they will hibernate until spring.

The next challenge for our team is to over-winter three Victoria plants kept in 6" (15 cm) containers as backups in our greenhouse throughout the summer. In late fall, these small plants (each with leaves averaging 8-10" [20-25 cm] in diameter) bloomed for the first time, with each flower measuring only 3-4" (7.6-10 cm) across. If all goes well, they will be added to our displays outdoors next summer.

Looking Forward

As we come full circle and eagerly await the season ahead of us, we look forward to once again hosting the IWGS New Waterlily Competition, and can't wait to see the stunning hybrids that will be entered this year. We will also be hosting the Garden Writers Association in September during the organization's annual conference in Raleigh, NC. This exciting event will follow the spring celebration of the 75th Anniversary of Sarah P. Duke Gardens. An early anniversary gift came this month with the recent naming of Duke Gardens as one of the top ten botanical gardens by Southern Living Magazine readers!  

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