Canadian Hemlock — Tsuga canadensis
Overview: Graceful, fine-textured evergreen with soft, flat needles and slightly drooping branch tips. Naturally pyramidal; one of the best conifers for shade and for sheared hedges or natural screens.
Size & habit: 50–70′ tall × 25–35′ wide at maturity (smaller in cultivation). Strong single leader; layered, feathery branching that can hold to the ground.
Growth rate: Slow–moderate (≈6–12″ per year once established; faster on cool, moist sites).
Hardiness: USDA Zones 3–7.
Light: Partial shade to shade (tolerates full sun in cool climates if soil stays evenly moist). Shelter from winter wind for best foliage.
Soil & water: Prefers cool, evenly moist, acidic, well-drained soils. Shallow-rooted—mulch 2–3″ (keep off trunk). Avoid drought, heat, and poorly drained/heavy soils.
Foliage, cones & bark:
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Needles ½–¾”, soft, flat, dark green with two pale bands beneath; arranged in flattened sprays.
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Small pendant cones ¾–1″, light brown.
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Bark gray-brown, becoming ridged with age.
Tolerance / concerns:
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Sensitive: Drought, heat, road salt, and drying winter winds.
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Pests: Hemlock woolly adelgid (HWA) is the key threat where present; also elongate hemlock scale and spider mites in hot/dry spells.
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Deer: Frequently browsed—protect young plants.
Pruning: Excellent for shearing and naturalistic thinning. Lightly trim after spring flush (and again mid-summer if needed). Can be cut back harder than most conifers (leave some green on each shoot). Maintain a single leader on trees.
Landscape uses: Shade-tolerant hedges, privacy screens, woodland backdrops, specimen near patios, and foundation softening where other conifers struggle.
Spacing (on-center):
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Formal hedge: 2–4 ft (start closer for quicker fill)
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Natural screen: 5–8 ft
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Specimen: allow 12–20 ft from structures/trees
Planting tip: Site with morning sun / afternoon shade if possible; plant with root flare at or just above grade; provide consistent deep watering for the first 2–3 seasons. In areas with known HWA pressure, plan preventive treatments or consider mixing in other shade-tolerant evergreens for resilience.
