Although giant sequoia is native to a small swath
of western slopes of the Sierra Nevada Mountains,
its hardiness (given most generously as Zone 6a
to 9b, with some sources constraining that range)
makes it suitable for use beyond its indigenous
terrain and indeed, it's been planted in many
western spaces, urban or otherwise. Like most trees
it prefers a loamy soil, even moisture, mid-range
pH, adequate soil volume, freedom from soil com-
paction, and full sun. However, it can grow in less
than these ideal conditions, and the more well-es-
tablished the tree, the better it will be able to ride
out periods of drought. Full sun appears to be the
least negotiable condition for giant sequoia.
Addressing the elephant in the room: how can a
giant sequoia, in all its massive glory, be considered
for urban spaces? Gordon Matassa is the Urban
Forestry Grant Project Coordinator in the Tree Services
Division of the Oakland, California Department of
Public Works. "If planted correctly in urban areas,
this species can bridge the natural world to the
cities that many of us call home," he says. "Giant
sequoia is well-suited for climate-appropriate urban
areas when given enough room to grow, such as
when planted in city parks. We have several giant
sequoias in our parks in Oakland, California, where
they stand out as sentinels in the urban landscape."
Giant sequoias are numerous in Portland, Oregon;
many of them were planted circa 1900. There are
seven Portland Heritage Tree program giant sequoias
in the City—some growing in parks, others in the
City right-of-way or in residential front and side
yards. The tallest of them is growing in Portland's Mt
Tabor Park; it's 200 ft (61 m) tall, with a 50 ft (15 m)
canopy spread and a 25.3 ft (7.7 m) trunk circumfer-
ence. (The genetic potential of giant sequoia's height,
given ideal conditions, can exceed 250 ft/76 m.)
According to the Portland Parks and Recreation
website, nearly 500 sequoias and redwoods have
Map showing (in red) limited native distribution of giant
sequoia (Sequoiadendron giganteum) on the western slopes
of the Sierra Nevada Mountains of eastern California. The
green areas indicate the natural range of coast redwood
(Sequoia sempervirens). Map in public domain
The fire-resistant bark of giant sequoia by Tom
DeGomez, University of Arizona, Bugwood.org
32 CityTREES
