Image for Mountain Hemlock

Mountain Hemlock

Scientific name

Tsuga mertensiana


Mountain Hemlock is a slow growing, coniferous tree species that typically grows between 20 and 30 m in height. This plant may also be known by the common names Alpine Hemlock or Black Hemlock. The bark is gray to reddish brown colored, deeply fissured, and scaly. The needles are grayish green colored, linear shaped, have tiny petioles, and appear radially around the stem with the densest on the upper side. The food and habitat provided by this tree are beneficial to many wildlife species, including birds and mammals. These trees are important for watershed protection because they capture runoff from snowmelt in high altitude areas. However, planted stock of this tree has low success and natural regeneration is usually best.

Planting conditions

Mountain Hemlock grows best in moist conditions with full or partial sun exposure. It prefers well-drained, cool, loam or rocky soils. It is tolerant to frost, shade, acidic pH, and nutrient poor soil. It is intolerant of dry conditions and calcareous soil. It is vulnerable to root rot and wind throw. This tree is naturally found in high altitude mountainous areas of the Pacific Northwest and is often inaccessible.


  • Plant height:
    • Any
    • Over 3m
  • Moisture level:
    • Moist
  • Light conditions:
    • Full sun
    • Partial sun
  • Soil type:
    • Loamy
    • Rocky
  • pH:
    • Acidic
    • Normal
  • Depth:
    • Potted
  • Eco Zone:
    • 2a
    • 2b
    • 3a
    • 3b
    • 4a
    • 4b
    • 5a
    • 5b
    • 6a
    • 6b
    • 7a
    • 7b
    • 8a
  • Plant type:
    • Tree
  • Height:
    • 20-30 m
  • Spread:
    • 5 m