UPDATING AN estate garden designed nearly a century ago by the Olmsted Brothers — one with its good bones still intact — might be intimidating. Garden designer Rick Kyper, however, plunged right in to transform the tired old garden using palm trees, vivid color and a fresh palette of plants.

The estate and its garden have a long history. "I don't know why I built so big a house," Seattle clothier Julius Redelsheimer said of the mansion he hired architect Julian Everett to design for him and his mother on Lake Washington. The estate ran 141 feet along the water, and the Georgian Revival-style home had 26 rooms. According to Lucile McDonald in her book, "Where the Washingtonians Lived," it was considered one of the most beautiful homes in the city when it was completed in 1914.

It was the second owner, Harry Ostrander, who hired the Olmsted Brothers to design the estate's gardens. The famed Massachusetts firm had already designed Denny Blaine Park next door to the property as part of the brothers' comprehensive park plan for Seattle.

The rectangular terraces, curving pathways and brick walls from the Olmsteds' original 1917 design still define the estate garden today. A glass-tile fountain in the back garden, a birdbath, the connection to the nearby park, mature trees and rhododendrons remain from the 1920s. But the waterfront slice of the property was sold off decades ago, and the original boathouse replaced with another home.

Steve Walker and Deborah Weasea bought the property in 1990. Walker, who passed away last winter, was a noted sculptor delighted to have found a home for his work. With garden rooms scaled large enough to accommodate his metal sculptures, a walk through the garden is a marriage of century-old bark and leaves set against sleek, contemporary metal.

"Before golf, we took care of the garden," is how Walker explained the couple's transition from gardeners to golfers. After becoming enamored of the game, Walker charged Kyper with updating and refurbishing the estate's gardens. "Steve told me to treat the place as if it was my own and have fun with it," remembers Kyper.

He left the mansion's formal gravel forecourt alone. The side gardens are rhododendron-shaded rooms featuring Walker's sculptures. In the back, Kyper let loose his love of plants and color. From spikes of Italian cypress to splays of palm trees, he carved a south-of-France feeling out of a mostly green Olmsted landscape. Evergreen magnolias, heucheras, brunnera and hostas fill in along and between pathways and paving, clothing the garden in glossy, colored or variegated foliage most of the year.

The formal lines of the rose garden remain, but Kyper ripped out the sick old roses and replaced them with season-spanning plantings. The original patterning of hedging and pathways contain tulips and hyacinths in spring. Azaleas hold sway a little later, followed by Rosa mutabilis, hydrangeas and perennials for summer flowers.

The garden's classical structure remains in place, as complementary to the lines of the house as it was nearly a century ago. But now the garden is plumped up with foliage year-round and blazes into colorful bloom from earliest spring through late autumn.

Valerie Easton is a Seattle freelance writer and author of "petal & twig." Check out her blog at www.valeaston.com. Mike Siegel is a Seattle Times staff photographer.