Pseudotsuga menziesii
Douglas fir
British Columbia south through Washington, Oregon, California; east to Rocky Mountains; sea level to 7,000+ feet (2,100+ m)Learn more
Overview
Pseudotsuga menziesii is a large to massive evergreen conifer native to western North America, the most commercially significant timber tree on the continent. Trees in cultivation typically reach 80–150 feet (24–46 m) tall and 20–40 feet (6–12 m) wide; in natural old-growth stands, trees exceed 200–325 feet (60–100 m). Growth rate is 24–48 inches (60–120 cm) per year in youth on good sites. The crown is broadly pyramidal when young, becoming columnar and open with age. Needles are flat, soft, aromatic, 0.75–1.5 inches (2–4 cm) long, dark green above with two white stomatal bands below, arranged spirally but appearing to radiate in all directions. Winter buds are reddish-brown, sharply pointed, and multi-scaled — among the most distinctive buds of any Pacific Northwest conifer. Cones are 2–4 inches (5–10 cm) long with three-pronged bracts exserted beyond each scale, a unique identification feature among all North American conifers. Bark on young trees is smooth and gray with resin blisters; on mature trees it is very thick, deeply furrowed, and corky, providing significant fire resistance. Pseudotsuga menziesii is not a true fir (Abies), hemlock (Tsuga), or spruce (Picea); the genus name means false hemlock.
Native Range
Pseudotsuga menziesii is native from British Columbia south through Washington, Oregon, and California, and east through Idaho and Montana to the Rocky Mountains, at elevations from near sea level to over 7,000 feet (2,100 m). It is native to the Pacific Northwest. The coastal variety (var. menziesii) and the interior Rocky Mountain variety (var. glauca) differ in needle color, cone size, and drought adaptation.Suggested Uses
Planted as a large specimen tree, windbreak, and reforestation tree in large-scale settings, spaced 20–30 feet (6–9 m) from adjacent plants. Provides significant wildlife habitat; old-growth specimens support spotted owls, marbled murrelets, and dozens of other cavity-dependent species. The three-pronged cone bracts are among the most memorable identification features of any North American conifer, making this tree of high educational value for forestry and botany curricula. Not appropriate for residential gardens of standard size.How to Identify
Appearance
Size & Dimensions
Height80' - 150'
Width/Spread20' - 40'
Reaches mature size in approximately 60 years
Colors
Bloom Information
Male cones are small, orange-red to yellow, cylindrical, in clusters at twig tips, releasing pollen in March–May. Female cones ripen over one growing season to pendant brown cones 2–4 inches (5–10 cm) long, opening in late summer to autumn to release winged seeds. Seeds are a significant food source for crossbills, nuthatches, chickadees, and Clark's nutcrackers. Cone production begins at 10–25 years; heavy cone years occur at intervals of 2–7 years.Detailed Descriptions
Flower Description
orange-red to yellow (male cones)Foliage Description
dark green above, two white stomatal bands belowGrowing Conditions
Sun Requirements
Requires 4-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Water weekly during the first two growing seasons; established trees are drought tolerant in coastal Pacific Northwest conditions. Prefers well-drained, slightly acidic soils; grows in clay, loam, and sandy substrates. Growth rate of 24–48 inches (60–120 cm) per year makes this unsuitable for small residential gardens; eventual height of 80–150 feet (24–46 m) or more requires clearance from all structures and power lines. Wind-resistant once established; the thick, corky bark of mature trees provides significant fire resistance. The interior variety (var. glauca) is more drought-tolerant than the coastal variety but slower growing. No fertilization required on adequate sites.Pruning
No pruning is required. Allow the natural pyramidal form to develop without intervention. Lower branch removal for clearance can be done in late fall or winter; cuts into the thick bark heal slowly. Avoid major pruning cuts on established trees. The central leader develops naturally and does not require training.Pruning Schedule
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