Scientific Name
Picea engelmannii ‘Engelmann Spruce’
Engelmann spruce is predominantly a tree of the Rocky Mountains in the United States and Canada, with a secondary range along the eastern slopes of the Cascade Range. In Colorado, it typically grows from around 9,000 feet in elevation up to the tree line, where it often takes on a dwarf, stunted form. The tree has a narrow, spire-like cylindrical shape. In landscaping, Engelmann spruce has long been overshadowed by Colorado blue spruce, which generally has a broader form and has produced far more cultivated varieties.
The foliage of Engelmann spruce is bluish green, though usually not as intensely blue as that of Colorado blue spruce. The needles are similarly sharp and prickly. In cultivation, these trees typically mature at around 60 feet tall. In mountain habitats, however, Engelmann spruce can grow much larger, with Colorado champion trees reaching 193 feet in height and trunk diameters of 40 inches.
As a species adapted to high elevations and heavy snowfall, Engelmann spruce tolerates Front Range winters with ease. Summer heat can cause stress, though generally not to the extent experienced farther east, where humidity and nighttime temperatures are much higher. The foliage texture is somewhat finer than that of blue spruce, and the seed cones of the two species are fairly similar in size, making them somewhat difficult to distinguish. One commonly mentioned identifying characteristic is that Engelmann spruce foliage is said to produce an unpleasant odor when crushed.
The wood of Engelmann spruce is a highly valued tonewood used in the construction of high-quality acoustic musical instruments.
The tree is named for George Engelmann, a German American physician and botanist who was one of the major figures in 19th-century North American plant science. An oak species and a pine species also bear his name. Based in St. Louis, Engelmann was closely associated with the founding of the Missouri Botanical Garden, often referred to as MOBOT.