Picea sitchensis (Sitka Spruce)


Michael's Opinion

The largest spruce in the world is the Sitka spruce. Reaching average heights between 30-60 m with a diameter at breast height (d.b.h) of about 2 m. Being light in weight and having high strength, the Sitka spruce is ideal for the production of construction materials.

Botanical Information

FamilyPinaceae
GenusPicea
Speciessitchensis
CategoryWoody
TypeTree (evergreen)
ReferencesHartmann, Hudson Thomas, Dale E. Kester, Fred T. Davies Jr, and Robert L. Geneve. Plant Propagation: Principles and Practices. Upper Saddle River, NJ: Prentice Hall, 2002. Print. Sargent, Charles Sprague. Manual of the Trees of North America, New York, New York: Dover Publications, Inc., 1965.Print
OriginWestern North America. Introduced by Victorian plant collector David Douglas who was employed by the Horticultural Society of London (later to become the Royal Horticultural Society) in the 1920’s. Douglas was killed under suspicious circumstances on his return from the Pacific North-West via Hawaii in 1834 at the age of 35.
Ethnobotanical Uses
Disclaimer
Construction materials.

Details

USDA Hardiness Zone4-9
USDA Hardiness Ref.
Canadian Hardiness Zone5-10
Canada Hardiness Ref.
RHS Hardiness ZoneH7-H3
RHS Hardiness Ref.
Temperature (°C)(-32) - (-1)
Temperature (°F)(-30) - 30
Height60 m
Spread6 m
GrowthFast
Flowering PeriodApril, May, June

Description and Growing Information

ShapeSymmetrical, open, loose and pyramidal. The base of the tree normally measures 1 m in diameter above the buttress base. Trees at maturity are clad in 0.5-1 m length lateral slender branches.
Propagation
CultivationCan withstand partial shade however, thrives in full sunlight with sandy, swampy soils, requiring moist soils; it is not drought tolerant.
PestsScale is common with this species as are aphids and mites.
Notable SpecimensQueets River, Olympic National Park, Washington, United States of America.
HabitatThe Sitka spruce grows in a thin strip along wet and rocky slopes of the west coast of North America from Alaska to California.
Bark/Stem DescriptionThe bark of this tree ranges in thickness from 0.5-1.5 cm. The bark is loosely attached at the surface. Young tree scales are reddish cinnamon in colour and mature to a deeper reddish brown.
Flower/Leaf Bud DescriptionThe buds are 0.5-15 cm in length, conical, acute or ovoid in shape. The scales are a pale brown chestnut colour in the winter. The tips are sharply pointed and reflexed above the middle.
Leaf DescriptionLeaves are 1-3 cm in length. Forming almost at a 90° angle around the branch, the stiff leaves are bluish grey with a white underside. Gradually tapering needles come to a sharp callous tip. Leaves are retained for 9-11 years.
Fruit DescriptionCone colour varies with the season. New cones are a yellow-green in colour and once fully grown will have a reddish brown colour. The shape of the cones is oblong-cylindrical. The cones are 10 cm in length. The seeds are smaller at the base and have oblong wings 0.8-1.5 cm long.

Photographs