Subalpine Fir

Synonyms: mountain fir, rough-coned fir

Subalpine Fir – a species of evergreen trees from the genus Fir (Ábies) of the Pine family (Pinaceae). In nature it grows in the high mountains of North America, from 33° to 63° N latitude at altitudes of 600-2050 m above sea level, up to the timberline. In nature it "coexists" with Engelmann spruce, whitebark pine (Pinus albicaulis), lodgepole pine (Pinus contorta), mountain hemlock (Tsuga mertensiana), as well as with other species. It lives 250-300 years. Cultivated since 1863.

It is a medium-tall tree 15-30 (48) m in height with a trunk diameter of 45-60 (90) cm. In the mountains it is lower-growing. The tree is slow-growing, especially in youth, with an average annual increment of 15 cm per year. At 100-200 years it reaches 15-22 m in height. Crown narrow-conical, narrow-skittle-shaped or columnar, dense.

Bark brownish or ash-gray, slightly fissured; on young trees smooth, silvery-gray. Young shoots ash-gray, shortly pubescent. Scaffold branches short, stiff, arranged in whorls. Root system wind-firm, superficial.

Buds spherical, very resinous. Needles short, 15-25 (36) mm long and 1.5 mm wide, with a rounded or obtuse tip, matte bluish-green above and with two white bands below, arranged irregularly in two rows, directed upward. Needles remain on the tree for 9 years.

Cones erect, numerous, cylindrical, contracted toward the apex, dark purple when young. They reach 6-10 cm in length and 3.5-4 cm in diameter. Bracts hidden. Seeds conical, wing dark, glossy, equal to the seed in length. Weight of 100 seeds is 10 g. Cones ripen in August – September. Produces abundant crops every 3 years.

Cultivars: Argentea, 'Compacta' (Glauca Compacta), Green Globe.

Hardiness zone: 5a

Location / Site: Prefers shady slopes or riverbanks. Grows well on fertile, moist, light or well-drained soil. Can also grow on poor and dry soil. Grows poorly on clay and heavy soils. Can tolerate short-term excess soil moisture. In Ukraine, in the southern steppe zone it often suffers from drought. May be damaged by spring frosts. In cultivation protection from direct sunlight is necessary. Resistant to heavy snowfall.

Planting: planting is best done in early spring (April) or autumn (late August - early September). Planting hole dimensions – 60x60 cm, with a depth of 60-80 cm. The root collar should be at ground level. Soil mix: leaf soil or humus, clay, sand, peat in a ratio of 3:2:1:1. On heavy soils drainage is necessary: crushed stone or broken brick, layer 20 cm. When planting you can add nitroammophoska in the amount of 250 - 300 g and 10 kg of sawdust per hole.

Pruning: formative pruning is not used – the crown forms naturally. Sanitary pruning is carried out in early spring before sap flow. Compact forms can be formed by pinching out the terminal buds of lateral shoots in autumn, and by shortening them in summer.

Care: fertilization is carried out in the 2nd-3rd year after planting. In early spring, under the mulch, apply granular fertilizer for conifers or Kemira-Universal (150 g/m²). Mainly only young trees are fertilized; mature trees do not require fertilization. The plant is moisture-loving and needs abundant watering 2-3 times per season; in dry periods water twice as often. During dry periods overhead watering of the crown at least once a week is also recommended. For uniform budburst abundant watering in early spring is recommended.

Diseases and pests: susceptible to fungal diseases

Propagation: by seeds or lignified cuttings. Considered difficult to root; cuttings do not root without rooting stimulants.

Usage: looks good in solitary and group plantings, in avenues and parks. When planted in groups or masses it effectively purifies the air, releasing essential oils and phytoncides. Widely used as a Christmas tree.