Tsuga Mertensiana
Mountain hemlocks are a species of tree that is part of the Pinaceae botanical family and the genus tsgua. They are a native tree to the west coast of North America and are very closely related to the western hemlock tree (tsuga heterophylla).
The scientific term mertensiana comes from a German botanist named Karl Keinrich Mertens, who was one of the first explorers to bring North American plant specimens back to Europe through a Russian expedition in the early 18th century.
Mountain hemlock trees a huge, long-living, but slightly slow growing. They are mostly known as being wonderful trees to witness on a trail run or a mountain hike, though they are sometimes cultivated as ornamental trees because of their attractive needle color and interesting crown shape.
The mountain hemlock is an evergreen conifer. This means that it possesses needles and cones instead of broadleaves and flowers, and its foliage will remain green and persist all year long, despite the season changes.
Hemlock trees are awesome. So are fruit trees, so are all trees! That’s why we created this huge list of 101 Types of Trees from all around the world. Not only because we wanted to learn more about them, but because we wanted to share all the cool information we discovered!
Related: Western Hemlock Tree | Eastern Hemlock Tree | Types of Hemlock Trees
What do Mountain Hemlock Trees Look Like?
Root System
Hemlock trees will develop two types of root systems. When they are first little saplings, they will start theirdft12 growth through a taproot, which is a large root that grows deep into the earth. Not only to create stability but to access moisture reserves deep in the earth.
The second root system will develop from the taproot. Dense and fibrous roots that grow wide-spreading and in a lateral formation. These roots help the tree access nutrients, and they also stabilize the tree from storms and windthrow.
Dimensions
Mountain hemlocks are large trees that will usually reach heights of 20 to 40 meters, depending on their growing location. When growing in the exact ideal conditions, some exceptional trees can reach 59 meters. A tree of medium height will have a trunk diameter of around 2 meters.
Growth Pattern
Young trees will have a slender, neat, and conic shape. Mountain hemlocks have a characteristically tilted lead shoot. Older trees will develop more of a cylindrical shape. Regardless of their age, all-mountain hemlock trees can be easily recognized by their pendulous branchlet tips.
Bark
Mountain hemlocks have bark that is a dark gray color. It grows in thin sheets and has cracks of square furrows.
Foliage
Mountain hemlock leaves are needle-like. These needles are around 1 inch in length, are slightly flattened, and are arranged spirally along with a shoot. They also have blunt tips and a soft texture, making them pleasant to the touch.
Mountain hemlock needles are a pale glaucous blue-green color, which is another way to easily identify them. They are different from other hemlock species through the presence of stomata on the upper surface of a needle.
How do Mountain Hemlock Trees Reproduce?
Cones
Hemlock trees are monoecious, meaning that a tree will produce both male cones (pollen cones – pollen-producing) and female cones (seed cones – ovule-producing).
Mountain hemlock cones are smaller relative to other hemlock species, though they tend to be longer, usually around 3 inches in length. They are a cylindrical shape and hang slightly pendulously on a branch.
A cone is covered in thin flexible scales. Immature cones are dark purple which then fades into a red-brown color. Cones are considered as being mature 5-7 months after their original pollination.
Seeds
A pollen cone will open up its scale to release pollen. That pollen will be wind-dispersed and brought to a seed cone of the same plant or of another plant. The scales of the seed cone will then close, and the ovule will become fertilized.
Through this fertilization, a seed will be produced. Mountain hemlock seeds are a red-brown color with a pale pink wing (to help with wind dispersal). Once a seed cone is mature, its scales will open up to release seeds.
Sexual Maturity
Mountain hemlock trees will usually start to produce seed crops around the age of 20. These are very long-lived trees (usually exceeding 800 years!) and they will experience their most productive seed crop years between the ages of 175 and 250, with high crop yields every 3 years, and moderate crops the years in between.
What are Some Other Hemlock Species?
The Western Hemlock Tree (Tsuga Heterophylla)
western hemlock trees are also sometimes known as the western hemlock spruce tree. They are a tree that is native to North America and are a very important member of the Pacific Northwest forests of the more coastal range. They are the largest of the hemlock species, usually obtaining heights of 50-70 meters. They are very closely related to mountain hemlock trees.
The Eastern Hemlock Tree (Tsuga Canadensis)
Eastern hemlock trees are also sometimes known as the eastern hemlock spruce tree. They are a native tree to the eastern side of North America, specifically Quebec and Nova Scotia, and running down towards Minnesota. They are a long-lived tree with moderately tall heights. They are restricted to the highland climates of the east coast.
The Carolina Hemlock Tree (Tsuga Caroliniana)
Carolina hemlock trees are native to the Appalachian mountains. They occur in rocky mountain conditions on slopes at high elevations. They are rather tall with an average of 35 meters in height, with characteristically thick and red-brown bark which stout branches.
Where do Mountain Hemlock Trees Grow?
Though they have very similar growing zones to the western hemlock tree, the mountain hemlock zone has a slightly broader range. Where the western hemlock tree is restricted to the most coastal ranges of the west coast, mountain hemlocks are able to grow in the Klamath Mountains and the Sierra Nevada.
They can be found growing in the rocky mountains of southern British Columbia, and southward to northern Idaho and western Montana. They grow at high altitudes in all ranges except for the far north locations. In Alaska (lower elevations) they will grow from sea level to 1000 meters in altitude. In the Oregon north cascade, they will grow from 1600-2300 meters in altitude. In the Sierra Nevada (higher elevations) they will grow from 2500-3100 meters in altitude.
Mountain hemlocks prefer to grow in cold and snowy subalpine forests. They also like cold maritime climates. They experience their best growth in cold winters and cool summers that experience high precipitation. These trees will often be found growing right at the treeline.
The mountain hemlock forest is commonly associated with western hemlock, Alaska cedar, western red cedar, lodgepole pine, subalpine fir, Pacific silver fir, and Engelmann spruce.
What are the Growing Conditions of Mountain Hemlock Trees?
Soil
The mountain hemlock prefers soils that are loose and have a coarse texture. The soil must be well-drained with moderate moisture content. They perform exceptionally well in British Columbia that has soil rich in acidic organic matter.
Sun Exposure
Mountain hemlock trees are rather tolerant of shade, which can sometimes be unusual for coniferous evergreens, as they are often sun-loving and shade-intolerant. Since the mountain hemlock seed and seedlings don’t have strict seed germination requirements, they are able to survive in shade.
Water Level
Mountain hemlocks prefer to have heavy annual precipitation and consistently moist soil. Much of this precipitation is from snow fall.
How are Mountain Hemlock Trees Used?
Ornamental
When growing outside of their natural range, the mountain hemlock tree is cultivated as an ornamental tree. They are appreciated for their lovely needle color and tolerance of extreme weather.
They are often planted as specimen trees in California landscapes, as well as in Scandinavian countries, and the United Kingdom as well.
FAQs
What is the average life expectancy of the mountain hemlock tree?
Mountain hemlock trees, like many other hemlock species, are rather long-lived. They have an average life expectancy of 500 years, but when they grow in the ideal conditions they can exceed 800 years.
How fast do mountain hemlock trees grow?
Mountain hemlocks are a moderately fast-growing tree and can grow between 12 and 24 inches annually.
How tall do mountain hemlock trees get?
Mountain hemlocks are large trees and will usually reach heights of 20 to 40 meters, depending on their growing location. When growing in the exact ideal conditions, some exceptional trees can reach 59 meters. A tree of medium height will have a trunk diameter of around 2 meters.
Can you eat hemlock bark?
According to Milk and Honey Herbs, the inner bark of the eastern hemlock tree has traditionally been used as survival food.
Where do mountain hemlock trees grow best?
Mountain hemlocks prefer to grow in cold and snowy subalpine sites. They also like cold maritime climates. They experience their best growth in cold winters and cool summers that experience high precipitation. These trees will often be found growing right at the tree line.
Is mountain hemlock wood hardwood or softwood?
Hemlock wood is high-quality softwood. Mountain hemlock wood is considerably harder and denser than other hemlock species.
Is mountain hemlock an evergreen tree?
Mountain hemlock trees are evergreen conifers. This means that they have cones and needles instead of flowers and broadleaves like most deciduous trees do. Their foliage will also persist all year long, whereas deciduous trees will drop their foliage seasonally.
Can hemlock trees grow in the shade?
Hemlock trees are quite a shade-tolerant species, which is slightly unusual for coniferous trees which usually shade intolerant.
How deep do the roots of the mountain hemlock tree grow?
Hemlock trees will develop two types of root systems. When they are first little saplings, they will start the growth through a taproot, which is a large root that grows deep into the earth. Not only to create stability but to access moisture reserves deep in the earth.
The second root system will develop from the taproot. Dense and fibrous roots that grow wide-spreading and in a lateral formation. These roots help the tree access nutrients, and they also stabilize the tree from storms and windthrow.
What soil type do mountain hemlock trees prefer?
The mountain hemlock prefers soils that are loose and have a coarse texture. The soil must be well-drained with moderate moisture content. They perform exceptionally well in British Columbia that has soil rich in acidic organic matter.
How do you identify mountain hemlock?
Young trees will have a slender, neat, and conic shape. Mountain hemlocks have a characteristically tiled lead shoot. Older trees will develop more of a cylindrical shape. Regardless of their age, all-mountain hemlock trees can be easily recognized by their pendulous branchlet tips.
Mountain hemlocks have bark that is a dark gray color. It grows in thin sheets and has cracks of square furrows.
Mountain hemlock leaves are needle-like. These needles are around 1 inch in length, are slightly flattened, and are arranged spirally along a shoot.. They also have blunt tips and a soft texture, making them pleasant to the touch.
Mountain hemlock needs are a pale glaucous blue-green color, which is another way to easily identify them. They are different from other hemlock species through the presence of stomata on the upper surface of a needle.
How many species of hemlock trees are there?
There are a grand total of 10 hemlock species.
Are mountain hemlock trees affected by woolly adelgid?
The woolly adelgid is a small sap-sucking pest that is closely related to an aphid. All hemlock species are affected by this pest, as it will attach itself to needles are suck out all of the plant nutrients that are crucial to the tree’s being.
When do mountain hemlocks start producing seeds?
Mountain hemlock trees will usually start to produce seed crops around the age of 20. These are very long-lived trees (usually exceeding 800 years!) and they will experience their most productive seed crop years between the ages of 175 and 250, with high crop yields every 3 years, and moderate crops the years in between.