While other gardeners pore over catalogs looking for backyard landscape ideas, Naperville's Kris Warren has a larger canvas. Each year, Warren chooses a color and design scheme for the Riverwalk's 37 flower beds.

"I call the Riverwalk my back yard," she said. "You come up with an idea, whether it's a color or a plant I like and everything plays off that." Warren has set the tone for the flower beds along the 4-mile path for the past six years. Her work is the first step in a planting program that
begins nearly a year before the first tulip pokes through the soil. This summer, Warren's big idea is an orange and yellow, double-flowered
hibiscus called Rosalind.The tropical trees and shrubs will appear near the Dandelion Fountain, Farmers Plow and in planters at Centennial Beach."These are hot, sultry colors, so I thought that would be fun," Warren said. "We've never done it in these numbers. It's difficult to find a
grower to supply them."The color scheme - orange, yellow and purple - also will play out in yellow and orange gazanias, purple angelonia and orange and white impatiens. Altogether, park district maintenance crews will plant roughly 15,000 annuals this month. The first shipment arrives Monday.

Flower studies
Warren's work begins well in advance of the spring planting season. In June or July, she visits gardens that display new plant varieties, such as the Ball Seed Co. trial gardens in West Chicago. She researches growers, prices and availability for the following year's plantings. She also tries to find something new - whether it's an unusual variety of plant or a new color theme."I tend to never do the same thing twice," Warren said. Enter hibiscus.

The park district has used hibiscus before, but only sparingly. Last fall, Warren was able to track down a Florida grower willing to add extra plants to a shipment to Midwestern garden centers. The long lead time for special orders means the district can't always react to recent trends. But serendipity can help. In June 2001, for example, Warren chose a planting theme of red, white and blue - which coincidentally became a fittingly patriotic display in 2002 after the terrorist attacks the previous fall. It doesn't always work out so well. With large trees and shrubs on the Riverwalk reaching the 20-year mark, some of the flower beds are becoming shadier. Sun-loving plants such as zinnias falter.

This spring, Warren anticipated beds full of purple tulips. Instead, many came up pink. Some tulips on the edges of beds never came up at all. "It was such a cold winter with no snow cover and so dry, that we've had some uneven growth," said north parks division foreman Chuck Papanos. "No two years are the same." Soil is key

To display the best crop of summer flowers, the park district begins early.Crews will soon start pulling out the faded daffodils and tulips and the
bulbs will be sold to local gardeners. Workers already are preparing the soil in other beds, the key to a vigorous display, Papanos said.
"Part of our success is we have spent a lot of time and money in soil preparation," Papanos said. "We've added compost to get a much higher
quality soil." The district adds mushroom compost and slow-release fertilizer to all its beds. Better soil means the plants will grow quickly and shade out weeds, Warren said. She also takes care to choose plants that don't require constant maintenance. "On the Riverwalk, some watering and weeding is fine, but we don't want to dead-head flowers all the time," Warren said. Throughout the summer, the 17-member Riverwalk maintenance staff will weed every week, water every other day and fertilize regularly. A couple times each summer, the park staff will critique what's working and what's not. "We have the advantage of a lot of eyes watching our plants," Papanos said.

The park district plans to add perennials where the Riverwalk needs more color, but the traditional flower beds will remain, Papanos said. The Riverwalk flowers were so impressive a few years ago the city asked Warren for help designing the planters downtown. She now designs the
downtown planting scheme every year as an independent contractor. An urban garden Flowers have always played a starring role on the Riverwalk. In 1981, when Naperville built the first stretch of the red-brick paths near Webster Street, benefactor Jim Moser insisted the park have flowers for its grand opening. The trouble was, construction didn't end until late August, when annuals such as impatiens and marigolds were unavailable. So Moser sent landscape architect Rick Hitchcock and the construction contractor to Holland, Mich., to hand-select mums showing early blooms. "It was sort of typical Jim Moser," Hitchcock said. "He was intent on making it as good as possible. As it turned out, it was really important. It made it look like a garden, which was his vision."

Today the Riverwalk is Naperville's most expensive park. Maintenance costs exceed $520,000 a year, including the flower budget. The
city and park district are sharing the costs through a new agreement reached this year. "We have a separate set of standards for maintenance on the Riverwalk that are much more intensive than any other park," said park district Commissioner Ron Ory, who also serves on the Riverwalk Commission. "That's because of its popularity," Ory said. "It's the most used park." Every now and then, Papanos likes to take a walk and soak up some compliments. "Everyone is always very appreciative," he said. "It's sort of hard not to be upbeat around here."