The tallest trees in the world are the coastal redwoods, or Sequoia sempervirens, according to National Geographic Magazine. They are found along the northern coast of California and the southern coast of Oregon, where they thrive in the very damp, cool weather and rich, fertile soil. These towering giants can reach upwards of 300 feet in their native habitat. Trees of this size are rare, however. In the world of landscaping, tall trees are defined as those that grow to 100 feet or more.
Giant sequoias (Sequoiadendron giganteum) are known as the largest trees in the world in sheer girth, but they also grow to great heights, stretching upwards of 300 feet, according to Reed College. These trees are only found growing in the wild along the west slopes of the Sierra Nevada mountains. These pyramidal-shaped trees have dense, dull green needles and rough, reddish brown bark.
Legend holds that it was a mountain ash (Eucalyptus regnans), which is native to Australia, that once held the record for the tallest tree in the world at a height of over 400 feet. This was back in the 1800s, when these trees were harvested in great numbers for their valuable hardwood. This record was never substantiated. Today, the mountain ash is considered to be the tallest hardwood tree in the world, according to the Australian Native Plants Society, and second in height only to the coastal redwood, which is a softwood tree.
The Sitka spruce (Picea sitchensis) is the largest and also one of the tallest trees in the world, with average heights of 180 feet and even larger, according to Virginia Tech University. The needles are small, stiff and an attractive blue-green color. The Sitka spruce is found primarily in the Pacific Northwest and along the coast of western Canada.
The Douglas fir (Pseudotsuga menziesii) is native to the Western United States and is found growing in the Rocky Mountains and the forests of the Pacific Northwest. This large, coniferous evergreen grows upwards of 150 feet in the wild but is a common landscape tree, where it remains at a much shorter height of around 70 feet tall, according to the University of Connecticut. This tree has a pleasing, pyramidal shape with rich green needles and is a favorite for use as a Christmas tree.