Rosa mulliganii blooming in the Sorbus Collection.
This included roses, cherries, crabapples and
mountain ash. By 1960, however, that land
had been appropriated for State Route 520
construction, and the roses were moved into the
collections at large. Most of them ended up on
the east side of the Arboretum, stretching from
the meadow through the Sorbus Collection.
Sunlight at a Premium
The fact that Woodland Park already had a
well-established rose garden (opened in 1924)
may have contributed to abandonment of the
Arboretum’s rose garden plans. Ray also says
there are many cultural reasons that roses are
not a focus for the Arboretum. Roses require
too much infrastructure, soil improvement and
drainage, and too much maintenance for the
small staff of gardeners working here. They also
require sunlight, which is at a premium in this
park full of trees.
Indeed, many of the roses you’ll see in the
Arboretum will be scrabbling up a tree to get
the desired sunlight. A pride and joy of the park
is Rosa mulliganii, a white-flowering Chinese
species named for former Arboretum director
Brian Mulligan, who sorted out its compli-
cated taxonomy. The best place to see it is in the
Sorbus Collection (also named for Mulligan),
where a number of cuttings dating to 1990 have
grown to impressive heights on top of some
collection trees and western red cedars. It is a
wonder to behold when in full bloom in June as it
towers 30 feet overhead. Stop for another visit in
the fall—when the foliage is a golden yellow and
the clusters of small hips have turned red—and
you will be as awed for a second time.
Mulligan described another rose in
our collection: Rosa wardii var. culta. It bears
red-centered white flowers with creamy yellow
stamens. A specimen dating to 1952 grows on
Crabapple Meadow. Ray says three new speci-
mens planted on the east side of the Wilcox
Bridge should produce a nice display of flowers
for the first time this year.
Serving the Conservation Mission
You don’t have to venture far from the Visitors
Center, though, to see and smell roses. There are
five lovely roses scrambling up the trees on the
east side of the main parking lot. Among them
Rosa roxburghii, or the sweet chestnut rose, stands
out for its unique prickly hips, which resemble
chestnuts. These hips have been found to have
antioxidant and antimutagenic properties.
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