Tsuga mertensiana
Common Name(s):
Previously known as:
- Abies mertensiana
- Hesperopeuce mertensiana
- Phonetic Spelling
- SU-ga mer-TEN-si-a-na
- Description
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Mountain hemlock is a medium-sized, needled, coniferous, evergreen tree in the pine family (Pinaceae). It is native to the southeastern coasts of Alaska and British Columbia, the mountains of Washington and Oregon and the high Sierras of California and Nevada. The genus name, Tsuga, originated from the Japanese word "tsu-ga," which means "tree" and "mother." The species name, mertensiana, is named in honor of German botanist Franz Karl Mertens.
The mountain hemlock prefers full sun and moist, cool summers. It is less tolerant to shade than the western hemlock. It does not perform well in the southeastern United States due to heat intolerance. This tree does best in areas where the growing season is short and the winters are cold and long. When the mountain hemlock is young, it may be pruned as a hedge. A mature tree reaches a height of 30 to 100 feet with a width of 10 to 15 feet. The tree may be propagated by seedlings, cuttings and layering.It has a conical or pyramidal crown, dense foliage, spreading branches, and the leading shoot may be tilted. The trunks of the tree are flexible and can withstand the weight of snow for months. After the snow melts, the trees will upright themselves. The tallest known trees have reached 175 feet, and the oldest trees are 500 to 1400 years old.
Use mountain hemlock in containers, a recreational play area or in a woodland landscape. It is great in a rock or winter garden. It can be used as a hedge for screening and privacy, and as a specimen tree.
Quick ID Hints:
- The branches turn upward at the tips.
- The needles are of equal length, dense on all sides of the stems in a bottle brush effect.
- The cones are narrow and long, measuring about 3 inches long and 1 inch wide. The seed cones are purple and then ripen to a grayish-brown.
Insects, Diseases and Other Plant Problems: The mountain hemlock has no serious disease problems. Potential pests include spruce spider mites and hemlock wooly adelgid.
VIDEO created by Ryan Contreras for “Landscape Plant Materials I: Deciduous Hardwoods and Conifers or Landscape Plant Materials II: Spring Flowering Trees and Shrubs,” a plant identification course offered by the Department of Horticulture at Oregon State University
- Profile Video:
- See this plant in the following landscape :
- Cultivars / Varieties:
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- 'Elizabeth'
spreading dwarf
- 'Elizabeth'
- 'Elizabeth'
- Tags:
- Cultivars / Varieties:
-
- 'Elizabeth'
spreading dwarf
- 'Elizabeth'
- 'Elizabeth'
- Tags:
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Attributes:
- Genus:
- Tsuga
- Species:
- mertensiana
- Family:
- Pinaceae
- Uses (Ethnobotany):
- The mountain hemlock is used primarily as an ornamental. Its wood is inferior to the western hemlock and is not typically used for lumber or pulpwood. This tree grows in high altitudes which also makes it difficult to access. Native Americans of the Pacific Northwest tribes used the leaves to make a poultice to treat burns. They used the bark to treat colds, flu, and nausea. The bark was also used for coloring their skin and tanning hides.
- Life Cycle:
- Woody
- Recommended Propagation Strategy:
- Layering
- Seed
- Stem Cutting
- Country Or Region Of Origin:
- Alaska to Western U.S.A.
- Distribution:
- Canada--British Columbia; U.S.--AK, CA, ID, MT, NV, OR, and WA.
- Wildlife Value:
- The seeds are eaten by birds and squirrels.
- Play Value:
- Wildlife Food Source
- Wind Break
- Dimensions:
- Height: 30 ft. 0 in. - 100 ft. 0 in.
- Width: 10 ft. 0 in. - 15 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Tree
- Woody Plant Leaf Characteristics:
- Needled Evergreen
- Habit/Form:
- Conical
- Pyramidal
- Growth Rate:
- Slow
- Maintenance:
- Low
- Texture:
- Fine
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Clay
- High Organic Matter
- Loam (Silt)
- Sand
- Shallow Rocky
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Good Drainage
- Moist
- USDA Plant Hardiness Zone:
- 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
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Fruit:
- Fruit Color:
- Brown/Copper
- Red/Burgundy
- Display/Harvest Time:
- Fall
- Summer
- Fruit Length:
- 1-3 inches
- Fruit Width:
- < 1 inch
- Fruit Description:
- The cones first appear in mid-May to mid-July. The male cones are bluish and less than 0.25 inches long. The female cones are cylinder-like, light to dark purple or brownish purple, and less than 3 inches long. The mature seed cones measure 1 to 3 inches long and 0.5 to 1.5 inches wide. They will ripen to a reddish-brown and have fan-shaped scales. The cones open from late September to November. The seeds are reddish-brown and about 2-3 mm long.
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Leaves:
- Woody Plant Leaf Characteristics:
- Needled Evergreen
- Leaf Color:
- Blue
- Gray/Silver
- Green
- Leaf Type:
- Needles
- Leaf Shape:
- Acicular
- Linear
- Leaf Margin:
- Entire
- Hairs Present:
- No
- Leaf Length:
- < 1 inch
- Leaf Width:
- < 1 inch
- Leaf Description:
- The leaf is a needle-type and measures 0.5 to 0.75 inches long, and the needles cover the branch on all sides, similar to a bottle brush. The needles are grayish-green or bluish-green, and the margins are entire.
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Bark:
- Bark Color:
- Black
- Dark Brown
- Red/Burgundy
- Surface/Attachment:
- Fissured
- Scaly
- Bark Description:
- The young bark is thin, scaly, and brown to black. The bark on mature trees is reddish-brown with deep fissures.
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Stem:
- Stem Color:
- Brown/Copper
- Gold/Yellow
- Stem Is Aromatic:
- No
- Stem Leaf Scar Shape:
- Round
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- The stems are slender to stout, yellow orangish-brown, and maybe smooth or densely hairy. The buds are oblong and are 3-4 mm long.
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Landscape:
- Landscape Location:
- Container
- Recreational Play Area
- Woodland
- Landscape Theme:
- Rock Garden
- Winter Garden
- Design Feature:
- Hedge
- Screen/Privacy
- Specimen
- Resistance To Challenges:
- Deer
