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
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
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
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.
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.
additional images >
Sarah P. Duke Gardens Web Site
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!