The following trees are native to Alaska. Alaska’s cold environment falls within USDA hardiness zones 1 to 7. Zone 1 covers much of the interior of the state while there are small pockets of Zone 7 along some of the coastal islands.
The black spruce grows to heights of 20 to 60 feet. This evergreen tree has blue-green needles with scaly bark. They enjoy marshy wet soil and are found throughout most of Alaska. The white spruce grows taller, to heights of 40 to 100 feet. It grows in a variety of soil types but shun the permafrost. The black spruce differs from the white spruce in a few ways. It has darker bark, shorter needles, smaller cones and prefers moister soil. The Sitka spruce is the largest, growing up to 160 feet tall. It has bluish green needles and thin scaly bark that can be brown to a purple-grey. It grows in coastal forests throughout southeastern Alaska, Kodiak Island, the Kenai Peninsula and Prince William Sound. It is the leading timber tree in Alaska because of its size and high-quality wood. Its wood was used to make the infamous Howard Hughes plane nicknamed “The Spruce Goose.”
Several varieties of hemlock grow in Alaska, including the Western hemlock and the Mountain hemlock. The Western hemlock grows to heights of 100 to 150 feet tall, making it the largest of the hemlocks. The top of the tree tends to droop to one side. The Western hemlock abounds in southern and southeastern Alaska, constituting 70 percent of the coastal forest. Its alpha cellulose is used to manufacture cellophane, rayon and yarn. The Mountain hemlock is smaller, growing anywhere from 30 to 100 feet tall. It grows in a variety of areas, including rocky, coarse and moist soil. It is typical of the high mountains, growing at elevations of up to 3500 feet. At such altitudes, it will grow more as a shrub.
There are 135 species in the family of birch trees, including alders. These deciduous trees have smooth bark. The paper birch has white bark with horizontal marks and grows up to 70 feet tall. This tree is found throughout the state of Alaska. It was used by Native Americans to make canoes. Today, it is used for making furniture and popsicle sticks.