My Trees > Mountain Hemlock 1

Tsuga mertensiana

Collected Mountain Hemlock from Mount Washington

Provenance

Collected from Mount Washington via Olympic NF permit

June 30, 2025

Dig Up – Acquired

Collected from Mount Washington, Olympic Penninsula, Had permit
August 30, 2024

Other – Died

Died after collection during hot dry weeks due to heat and insufficient collected roots
August 13, 2023

Observation

High-altitude conifer with silvery needles; elegant but slower-growing; best for upright styles.

Leaf Persistence: Evergreen
Leaf Form: Conifer
Watering: Moderate
Watering Notes: Moisture retention critical; mulching is beneficial.
Watering Season: Spring → Autumn
Fertilization: Balanced
Fertilization Notes: Balanced feed early and late in season; avoid midsummer feeding.
Wiring: Spring or Autumn
Wiring Notes: Thin bark - pad wire carefully and adjust seasonally.
Pruning: Maintenance throughout growing season; structural in spring
Pruning Notes: Best pruned after flush hardens; avoid deep cuts into bare wood.
Repotting: Every 3-5 years
Repotting Notes: Repot in cool weather; mist frequently afterward.
Propagation: Cuttings or seed
Propagation Notes: Slow to root; air layering preferred for mature specimens.
Zone 8b: Watch for spider mites (Jul-Aug); Prevent rot in wet Nov-Jan

Placement: Full sun to partial shade
Placement Notes: Tolerates more sun than other Tsuga but still benefits from shade.
Winter Notes: Hardy, but prolonged freeze can damage fine root tips.
Summer Notes: Water early in the day; maintain high ambient humidity.