Scientific Name
Cedrus atlantica ‘Glauca’
This tree can be difficult to distinguish from the fabled cedar of Lebanon, although it is native only to the Atlas Mountains of Algeria and Morocco. It is one of the few trees of African origin that can be grown in climates as cold as Denver’s. However, that is less surprising considering that the Atlas Mountains reach elevations of more than 13,000 feet and are located at about 35 degrees north latitude, roughly as far north as Albuquerque, New Mexico. In their native habitat, these trees can surpass 100 feet in height and develop trunks more than 6 feet in diameter. Though they can grow quite large in U.S. cities with more moderate climates than Denver, here they have so far only just surpassed 40 feet. The Colorado champion tree at Loyola Hall is about that height.
This cedar is well adapted to the hot, dry conditions that characterize our summers. However, it has a major vulnerability because it does not have quite the winter cold hardiness needed for this region. It may be seriously injured when temperatures drop below minus 10 degrees Fahrenheit or when temperatures fluctuate extremely rapidly, making its use risky outside the warmest parts of the region. Even in its protected location at Regis, this tree suffered some damage from a sudden temperature drop in 2023 that killed some of its new shoot growth, but it has since recovered nicely.
The foliage of these cedars consists of short needles that occur singly on new growth and in tufted clusters that angle slightly upward on older growth. The designation ‘Glauca’ refers to the more ornamental light blue-gray needle color of most trees available for sale, in contrast to the more typical green of trees in their native habitat. Young Atlas cedars usually have a gaunt appearance but fill out well as they develop. While they maintain a roughly pyramidal form for many years, they tend to develop a flat, layered canopy as they mature. Small, upright, finger-shaped male cones are concentrated on the lower parts of the tree and release clouds of pollen in the fall, unlike most other conifers. The stouter female seed cones are also upright and are usually found in the upper canopy. After the seeds are released, the female cones disintegrate and leave little trace behind. True cedars of the genus Cedrus are native only to Asia and Africa. However, the term “cedar” is also commonly used for various North American conifers that botanically are junipers, arborvitae and other species.