Overview of Concolor Fir
Concolor fir, Abies concolor, (also known as white fir) is an excellent choice for Midwestern landscapes, both for aesthetics and being one of the most adaptable firs. Native to the western United States, concolor fir can reach heights of 130 to 150 feet and may occasionally reach 350 years of age. It can be found from 6,000 ft. to 11,000 ft. elevation in the Rocky Mountains in Colorado and New Mexico to the Coast Range in California and Oregon. Near the Pacific Coast it can occur as low as 2,300 ft. elevation. In typical home landscapes, concolor fir reaches 30 to 70 feet tall and 15 to 30 feet wide when mature.
Concolor fir, which is grown commercially as a Christmas tree, features an almost perfect pyramidal shape with horizontally tiered branches when young. At maturity trees develop a dome-like crown. Needles are short, flat, and soft (unlike spruce), with a slight curve to them, and they are silvery blue-green both above and below. Undersides may have a whitish bloom. Needles also feature a pleasant slight citrus smell when broken. The smooth gray bark develops attractive deep, irregular furrows and irregular, flattened scales on mature trees. Oblong cones are held upright (a trait of the true firs) and vary in color from yellow green to purple. Cones mature in one season and generally disintegrate after the seeds are shed, falling off the tree in September and October.
Landscape Use of Concolor Fir
Concolor fir is a fairly slow-growing, drought-resistant tree that does best in deeper, well-drained soils. Avoid planting in heavy clay and wet spots, such as near over-irrigated lawns. Concolor fir is tolerant of some shade, although it prefers full sun, and is hardy in zones 3a to 7b.
This is a very desirable landscape species, but it may need some protection on very windy, exposed sites. Because of its dense growth it does not need any pruning to keep its shape. With its conical form, blue-green foliage and lack of insect or disease problems, it can be used as a substitute for Colorado blue spruce (Picea pungens), which is prone to Rhizosphaera needle cast disease in Wisconsin.
– Susan Mahr, University of Wisconsin – Madison
Last Update: Bruce Spangenberg, UW-Madison Extension, 2026
