Common Name: Colorado Fir

General Information

Abies concolor is an evergreen tree with a long, narrow crown; it can grow from 45 - 55 metres tall, sometimes more. The straight, cylindrical bole can be 100 - 200cm in diameter[].
The tree provides a useful timber and is ofen harvested from the wild and traded. A very ornamental tree, many dwarf forms have been developed for horticultural use, and the tree is sometimes grown as a 'Christmas tree'[, ].
Abies concolor is an extremely widespread species that occurs in numerous locations throughout much of the mountainous western North America and, more scattered, into Mexico. Whilst undoubtedly logged in past and present, this has little impact on the total population. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

, ,

Range

South-western N. America - Oregon to California, to Arizona and New Mexico

Habitat

Found on a wide range of soils, but preferring moist soils with a humid climate and a long winter from 700 metres to 3,400 metres[].

Properties

Conservation Status	Least Concern
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	45.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

A plant of the temperate to subtropical zone, where it is found at elevations up to 3,100 metres. It grows best in areas where annual daytime temperatures are within the range 0 - 18°c, but can tolerate 5 - 22°c[]. When dormant, the plant can survive temperatures down to about -20°c, but young growth can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 800 - 1,200mm, but tolerates 350 - 1,900mm[].
Prefers a good moist but not water-logged soil[]. Grows well in heavy clay soils. Plants are very shade tolerant but growth is slower in dense shade[]. Intolerant of atmospheric pollution[]. Prefers a pH in the range 4.5 - 6.5, tolerating 4 - 7[]. Prefers slightly acid conditions down to a pH of about 5[]. Prefers growing on a north-facing slope[]. Trees succeed on poor dry sites in the wild[]. Trees are shallow rooted and therefore liable to be wind-blown in exposed sites[].
Trees are not very tolerant of air pollution and therefore seem best suited for suburbs or rural areas[]
New growth is from late spring to mid summer, and trees are virtually never damaged by late frosts or aphis[, ].
Trees can live for 300 - 400 years[].
Most trees of this species that are grown in Britain are in fact the sub-species A. Concolor lowiana. (Gordon.)Lemmon. This form tends to grow better in Britain than the type[].
There are two basic forms of this sub-species, those from the north of the range are vigorous in height growth whilst the southern form is vigorous in girth growth[]. They both have a potential for forestry use in Britain[].
Trees should be planted into their permanent positions when they are quite small, between 30 and 90cm in height. Larger trees will check badly and hardly put on any growth for several years. This also badly affects root development and wind resistance[].
Plants are strongly outbreeding, self-fertilized seed usually grows poorly[]. They hybridize freely with other members of this genus[].
The crushed leaves have a strong lemony scent[].

Edible Uses

None known

Medicinal

The pitch from the trunk has been used as an antiseptic poultice for cuts, wounds etc[]. An infusion of the pitch, or the bark, has been used in the treatment of TB[].

An infusion of the foliage has been used in a bath for relieving rheumatism[].

An infusion of the pitch and leaves has been used in the treatment of pulmonary complaints[].

Agroforestry Uses:

The tree is a good soil stabilizer and may be particularly useful on road cuttings[]

Other Uses

A tan coloured dye can be obtained from the bark[].

An extract of the leaves, branches and wod is used as an ingredient in commercial cosmetic preparations as a masking agent[].

Wood - very light, not strong, coarse grained, soft, not durable. Used mainly for pulp, cases etc, it is also used for general construction applications and plywood[, , , ]. It is sometimes used in framing small houses but is not strong enough to be used in larger buildings[]. The wood lacks a distinctive odour and so does not impart a flavour to items stored in it - thus it can be used for making tubs for storing food items[].
The wood is often used for fuel, though it is not a very good one[].

Propagation

Seed - sow late winter in a greenhouse or outdoors in early spring[]. Germination is often poor, usually taking about 6 - 8 weeks[]. Stratification is said to produce a more even germination so it is probably best to sow the seed in a cold frame as soon as it is ripe in the autumn[, ]. The seed remains viable for up to 5 years if it is well stored[]. When large enough to handle, prick the seedlings out into individual pots and grow them on for at least their first winter in pots. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Alternatively, if you have sufficient seed, it is possible to sow in an outdoor seedbed. One report says that it is best to grow the seedlings on in the shade at a density of about 550 plants per square metre[] whilst another report says that they are best grown on in a sunny position[].