Douglas-fir — Pseudotsuga menziesii
Overview: Stately, narrow-pyramidal evergreen with soft, fragrant needles, coppery pointed buds, and signature pendant cones with three-pronged bracts. Durable and fast to establish on well-drained sites; excellent specimen, windbreak, or Christmas tree.
Size & habit: 60–100′ tall × 20–30′ wide (smaller in cultivation). Strong central leader; horizontal to slightly upswept branches; holds lower limbs for many years.
Growth rate: Moderate to fast (≈12–24″ per year on good sites).
Light: Full sun (very light shade tolerated when young).
Soil & water: Prefers well-drained, slightly acidic loams or sandy loams. Handles coarse, drier soils better than heavy clay. Avoid waterlogged or compacted sites. Moderate drought tolerance after establishment.
Foliage, cones & bark:
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Needles ¾–1¼”, soft, flattened; blue- to blue-green, pleasantly resinous-citrus aroma when crushed.
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Cones 2–4″, tan-brown, hanging; each scale bears a conspicuous trident bract.
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Bark gray-brown, thickening and furrowing with age.
Tolerance / concerns:
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Tolerant: Cold, wind, lean soils (especially var. glauca).
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Sensitive: Chronic wet feet, high road salt, stagnant humid air.
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Diseases (humid regions): Rhabdocline needle cast (primary), occasional Swiss needle cast—site in full sun with good air flow; avoid overhead irrigation.
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Insects: Aphids, mites, Cooley spruce gall adelgid (risk higher near spruces).
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Deer: Usually avoided once taller; protect leaders when young.
Pruning: Minimal. Maintain a single leader; remove dead/crossed wood just after spring flush. Do not shear (outside Christmas-tree culture).
Landscape uses: Four-season specimen, large-scale anchor, windbreaks on drier interior sites, and premium Christmas tree plantations.
Spacing (on-center):
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Specimen / large anchor: 15–25 ft
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Windbreak / screen: 12–16 ft
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Christmas-tree plantations: 6–8 ft
Planting tip: Set the root flare at or slightly above grade; on marginal/heavy soils, plant on a slight berm for drainage. Maintain a weed-free mulch ring (2–3″, off the trunk) and deep, periodic watering during the first 2–3 seasons.
Lincoln National Forest var.
High-elevation interior-Southwest provenance favored for dry-site toughness, sun/heat resilience, uniform, dense form, and attractive blue-green color. Typically hardy to Zone 4 (locally 3 with snow cover); still requires well-drained soils and open, breezy, full-sun sites to limit Rhabdocline in humid regions. Ideal for specimens and Christmas-tree plantings where summers are sunny and soils are not heavy or wet.
