Lilies That Rate

International water lily contest takes root at Duke.
October 1, 2009
Nurturing nature: Horticulturist Kilbane tends

Nurturing nature: Horticulturist Kilbane tends to hardy and perennial lily competitors. Michael Zirkle

Sharing pond space with the bullfrog is a sprinkling of water lilies, some with vibrant blooms, others with swelling buds, a few with nothing more than surface leaves. Each plant is identified by a cryptic sign: Tropical #3. Hardy #1. The frog-seeking group doesn't seem to notice the lilies. Neither does a young Japanese couple who take turns posing for pictures in front of the pond. A third set of visitors descends from the garden terraces. A boy in the group spies the Victoria lilies, with their large, round, low-rimmed, thorn-encrusted leaves, and throws a pebble at the leaf, aiming for dead center.

Nurturing nature:

Nurturing nature: contest entries identified by numbered signs. Michael Zirkle.

Standing nearby, Tamara Kilbane shakes her head and manages a resigned smile at the not uncommon sight. As the gardens' aquatic plant horticulturist, Kilbane oversees the health and vitality of various ponds and pools throughout the fifty-five-acre expanse. More than 300,000 people visit the gardens every year; it's no surprise that some of them treat the environs with less reverence than others. But in the case of the delicate water lilies, there's more at stake than just protecting nature's glory.

A few days earlier, Kilbane had installed the signs to mark this year's entries in the International Waterlily & Water Gardening Society (IWGS) New Water Lily Competition. Duke Gardens is hosting the contest for the fourth year in a row, and as in the past three years, visitors to the gardens—or the gardens' website—can vote for their favorites. Although the official judging is conducted by a team of international water lily experts, the popular vote helps the IWGS and lily growers know what appeals to consumers, while enhancing public awareness of the innumerable variety within the Nymphaea genus.

In addition to young boys engaging in target practice and other human meddlers, the natural enemies of the gardens' aquatic flora are oxygen-sucking algae and hungry turtles and ducklings. Kilbane and her crew of volunteers do their best to ward off damage, but she says it's always a tradeoff. The goldfish pond was built in the 1930s without the now-standard liners and recirculation pumps found in most modern water gardens.

It's leaky, so water from the nearby duck pond is diverted into the site, making it prone to algae. A small portable fountain runs continually to break up the water's surface and inhibit algae growth. Lilies like full sun for at least six hours a day, so the goldfish pond seems like the perfect location. Except that lilies also prefer still water, and the small portable fountain installed to inhibit algae growth does so by sending continuous ripples across the water's surface.

Kilbane takes it all in stride. "Last year the blue herons discovered they could stand on the Victoria leaves and do their fishing from there, so we lost a number of goldfish," she says. "Another time, a volunteer told me she saw a woman bending down to remove one of the lily competition entries from Thailand."

Rather than fret about the inherent hazards of displaying sumptuous floral specimens in a public setting, Kilbane embraces the educational component of her job, patiently explaining the differences between tropical and hardy lilies. "Tropicals usually have thinner-edged leaves, and their flowers are showier and higher off the surface than the hardies. But hardies are perennials—they die back and return in the spring—whereas tropicals are annuals in this area and are saved and stored as tubers at the end of each summer."

She says that growers, or "hybridizers," seek new and unusual combinations of bloom colors and sizes (very large, very small), petal shapes (pointed, rounded), and timing of blooms (day, night). "Both tropicals and hardies only bloom for three to five days," she says. "Some start out white the first day and then turn pink on the second or third day. Others have more of a sunset palette, going from light yellow to a deep orange."

Kilbane mentions Pairat Songpanich, a grower in Thailand who won Best New Hybrid in the 2006 and 2007 IWGS competitions for his hardy Nymphaea tan-khwan and Nymphaea miss siam, respectively. He "just developed the first hybrid blue water lily, something hybridizers have been trying to do for almost 100 years," she says.

This year there are twelve entries in the IWGS competition, four tropicals and eight hardies. They come from as far away as Cyprus and as close by as Florida. If shipped from outside the continental U.S. and Hawaii, they must be sent as bare root plants; otherwise, they arrive in pots. "Since you can't send soil internationally, we recommend that people sending us entries from outside the U.S. treat their plants with fungicide and ship them as fast as they can," she says. "The last thing you want is to have them stuck in customs for three weeks and die."

Once the entries arrive, in early spring, Kilbane and her colleagues plant them in sturdy pots and position them on metal stands in the goldfish pond, where they will bloom from late June through late September.

The plants are on a weekly maintenance, biweekly fertilizer schedule. Kilbane and volunteers don waders every Thursday to rid plants of dead leaves and blooms and to reposition the pots, providing more space between plants as they grow.

An interactive sign at the left edge of the goldfish pond shows what each entry looks like in full bloom—essential, since not every plant has a flowering bloom every day—and provides entry forms and pens for people to mark their favorite. The IWGS judges will not actually visit Duke Gardens; instead, Kilbane sends photographs of each plant's first-, second-, and third-day blooms, along with the leaves and the entire plant's growth habit.

Kilbane, who found her professional calling while mucking around ponds on her grandfather's dairy farm in Oregon, says she's not sure which hardy will win this year, but she's pretty sure about the top tropical.

"I expect entry number two to win both the popular and judges' votes," she says, noting that the decisions of the professionals and the public tend to mirror each other. Tropical #2 was entered last year, but didn't win and, under IWGS rules, is eligible for another try.

What is it about this particular tropical that gets Kilbane's informed vote? Is it the spiky leaves, the contrasting yellow center of the violet bloom, or the perky shape of the buds?

"It's bright purple," she says, "and people like purple."