Scientific Name
Cedrus atlantica v. glauca
The blue atlas cedar is a large, highly ornamental conifer that is often indistinguishable from the fabled Cedar of Lebanon. Although they look nearly identical, this species is native only to the Atlas Mountains of Algeria and Morocco. As such, it is one of the few trees of African origin that can be grown as far north as Denver with its cold winters. However, that is less surprising considering that the Atlas Mountains reach heights over 13,000 feet and are located about 35 degrees north latitude, which is as far north of the equator as Albuquerque, New Mexico. In native haunts, these trees can surpass 100 feet in height and can develop trunks over six feet in diameter. While this species can grow significantly larger in U.S. cities with milder climates, Denver specimens have only recently surpassed the 40-foot mark. This height is shared by the Colorado state champion in Westminster and the second-place champion located in the Loyola Hall courtyard at Regis University.
These cedars are very adapted to hot and dry conditions that resemble Colorado summers. However, they have a major vulnerability not having quite the cold hardiness needed here, as they may be seriously injured if temperatures drop below minus 10°F or when there are extremely rapid fluctuations in temperature. Planting is risky in all but the warmest parts of our region. The Regis tree suffered damage from an abrupt temperature plunge several years ago, and there was some question about its prognosis, but it’s been on the road to recovery since then.
The foliage of the cedars consists of short needles that occur singly on new growth and in tufted clusters that angle slightly upward from side spurs on older growth. The designation 'Glauca' refers to the light blue-gray needle color on most trees available in commerce, in contrast to the more typical green of trees in native habitat, a color that is also typical of the other cedar species. Young atlas cedars usually have a gaunt appearance but fill out well as they develop. While they will maintain a roughly pyramidal form for many years, eventually they tend to develop a flat to layered upper canopy structure with maturity. Their small upright finger-shaped pollen (male) cones concentrated on the lower parts of the tree release clouds of pollen in the fall, which is unlike the pollen release timing of many other conifers. The thicker female seed cones, also upright in contrast to the more familiar hanging seed cones of pines and spruces, are usually found in the upper canopy. After the seeds are released, the cones disintegrate and little trace of them remains for long.
True cedar trees such as this one (genus Cedrus) are native only to Asia and north Africa. However, the term "cedar" is in common usage to refer to various North American native conifers that botanically are junipers, arbor vitae or etc.