Tsuga heterophylla

Common Names

Western Hemlock, Pacific Hemlock, West Coast Hemlock

Summary

Western Hemlock (Tsuga heterophylla) is an evergreen conifer native to the Pacific Northwest, from Alaska to northern California, often forming a tall, narrow to broad crown with pendulous branch tips. It has flat needles 5–20 mm long with two white bands on the undersides, small ovoid cones, and dark brown to reddish-brown bark with deep furrows, plus a drooping leader that gives a graceful silhouette. It is highly shade-tolerant and thrives in moist, acidic soils with good drainage, reaching substantial height in favorable conditions.

In cultivation it prefers moist, well-drained soil and tolerates a wide range of sun to shade, with regular watering through the first two growing seasons. Propagation is by seed or cuttings, though stratification of about 90 days at 4°C (40°F) improves germination; seeds can be stored for several years. In landscapes it serves as a specimen, screen, or hedge, and is valued for ornamental evergreen foliage as well as timber and pulp production; it provides wildlife habitat and seeds are wind-dispersed. Pests such as hemlock woolly adelgid can affect some populations.

Lifecycle

Perennial

Height

1800-2340 inches

Spread

12-40 feet

Hardiness Zones

Zones 5a-8b

Sunlight Requirements

Ideally Full Sun; tolerant of Partial Shade to Full Shade.

Soil Type

Moist, well-drained, acidic, loamy, humus-rich soil

Soil Drainage

Moist but well-drained soil

Soil pH

4.5-5.0, acidic soil (pH less than 6.0)

Bloom Color

Yellow

Bloom Time

Spring

Foliage Color

Green foliage, often yellow-green on the upper surface with white on the lower surface

Fall Foliage Color

Green

Leaf Lifecycle

Evergreen needle

Growth Rate

50–120 cm per year once established, initial growth is slow

Seasons of Interest

Spring, Summer, and Fall

Propagation Methods

Seeds, Layering, Cuttings

Attracts Wildlife

Attracts birds