Introduction:
Douglas-Fir grows 40 to 60 feet and spreads 15 to
25 feet in an erect pyramid in the landscape.
It grows to more than 200 feet tall in its native habitat
in the West. Hardiness varies with seed source, so be
sure it was collected from an area with suitable coldhardiness
to the area in which it will be used.
Specifics:
Scientific name: Pseudotsuga menziesii
Pronunciation: soo-doe-SOO-guh men-ZEE-zee-eye
Common name(s): Douglas-fir
Family: Pinaceae
USDA hardiness zones: 5 through 6
Origin: native to North America
Uses: screen; specimen; Christmas tree; no proven urban tolerance
Availability: generally available in many areas within its hardiness range
Pronunciation: soo-doe-SOO-guh men-ZEE-zee-eye
Common name(s): Douglas-fir
Family: Pinaceae
USDA hardiness zones: 5 through 6
Origin: native to North America
Uses: screen; specimen; Christmas tree; no proven urban tolerance
Availability: generally available in many areas within its hardiness range
Description:
Height: 40 to 60 feet
Spread: 15 to 25 feet
Crown uniformity: symmetrical canopy with a regular (or smooth) outline, and individuals have more or less identical crown forms
Crown shape: pyramidal
Crown density: moderate
Growth rate: medium
Texture: fine
Spread: 15 to 25 feet
Crown uniformity: symmetrical canopy with a regular (or smooth) outline, and individuals have more or less identical crown forms
Crown shape: pyramidal
Crown density: moderate
Growth rate: medium
Texture: fine
Foliage:
Leaf arrangement: alternate; spiral
Leaf type: simple
Leaf margin: entire
Leaf shape: needle-like (filiform)
Leaf venation: none, or difficult to see; parallel
Leaf type and persistence: evergreen; needle leaf evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no fall color change
Fall characteristic: not showy
Leaf type: simple
Leaf margin: entire
Leaf shape: needle-like (filiform)
Leaf venation: none, or difficult to see; parallel
Leaf type and persistence: evergreen; needle leaf evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no fall color change
Fall characteristic: not showy
Trunk and Branches:
Trunk/bark/branches: droop as the tree grows, and
will require pruning for vehicular or pedestrian
clearance beneath the canopy; not particularly showy;
should be grown with a single leader; no thorns
Pruning requirement: needs little pruning to develop a strong structure
Breakage: susceptible to breakage either at the crotch due to poor collar formation, or the wood itself is weak and tends to break
Current year twig color: green Current year twig thickness: medium; thin
Pruning requirement: needs little pruning to develop a strong structure
Breakage: susceptible to breakage either at the crotch due to poor collar formation, or the wood itself is weak and tends to break
Current year twig color: green Current year twig thickness: medium; thin
Culture:
Light requirement: tree grows in full sun
Soil tolerances: clay; loam; sand; acidic; alkaline; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: low
Soil salt tolerance: poor
Soil tolerances: clay; loam; sand; acidic; alkaline; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: low
Soil salt tolerance: poor
In Depth:
The tree prefers a sunny location with a moist soil
and is not considered a good tree for much of the
South. It grows but struggles in USDA hardiness zone
7. Douglas-Fir transplants best when balled and
burlapped and has a moderate growth rate. It tolerates
pruning and shearing but will not tolerate dry soil for
extended periods. Protect from direct wind exposure
for best appearance. Some occasional watering in
summer dry spells will help the tree stay vigorous,
especially in the southern end of its range.
Cultivars are: ‘Anguina’ - long, snake-like branches; ‘Brevifolia’ - short leaves; ‘Compacta’ - compact, conical growth; ‘Fastigiata’ - dense, pyramidal; ‘Fretsii’ - dense bush, short broad leaves; ‘Glauca’ - bluish foliage; ‘Nana’ - dwarf; ‘Pendula’ - long, drooping branchlets; ‘Revoluta’ - curled leaves; ‘Stairii’ - variegated leaves.
Pests:
Aphids infestations on small trees may be dislodged with a strong stream of water from the garden hose.
Scale and bark beetles may infest Douglas-Fir, especially those under stress.
Root rot can be a serious problem on clay and other wet soils.
Needles infected by leaf cast fungi in spring turn brown and fall off.
Several fungi cause canker diseases leading to branch dieback. Maintain tree health and prune out infected branches.
Cultivars are: ‘Anguina’ - long, snake-like branches; ‘Brevifolia’ - short leaves; ‘Compacta’ - compact, conical growth; ‘Fastigiata’ - dense, pyramidal; ‘Fretsii’ - dense bush, short broad leaves; ‘Glauca’ - bluish foliage; ‘Nana’ - dwarf; ‘Pendula’ - long, drooping branchlets; ‘Revoluta’ - curled leaves; ‘Stairii’ - variegated leaves.
Pests:
Aphids infestations on small trees may be dislodged with a strong stream of water from the garden hose.
Scale and bark beetles may infest Douglas-Fir, especially those under stress.
Root rot can be a serious problem on clay and other wet soils.
Needles infected by leaf cast fungi in spring turn brown and fall off.
Several fungi cause canker diseases leading to branch dieback. Maintain tree health and prune out infected branches.
