| General Description | Larix occidentalis is a large deciduous conifer prized for its strong, no-knot timber. Larix occidentalis can grow up to 70 m (230 feet) when fully mature. These trees are very hardy and can live for hundreds of years. The colour of Its bark is reddish brown when mature and is made up of large scaly plates. In the fall, its needles go from green/pale green to bright yellow. |
| ID Characteristic | The cones of Larix occidentalis are dark reddish brown, with an extended bract tipped scales; similar to cones of Fir (Abies). Its reddish brown trunk can grow to be 1.5 m (150 cm) in diameter. Being a deciduous conifer, its densely clustered needles go from a pale green/green to bright yellow in the autumn. |
| Shape | Tall, Pyramidal shape. These characteristics are consistent throughout all of its growing periods. |
| Landscape | Larix occidentalis can be used as a specimen tree, as well as being a good choice for bonsai plantings. |
| Propagation | Larix occidentalis requires stratification at temperatures of 40 F (4 C) for 60 days. Best germination rates are on mineral type soils as close to where is grows natively as you can get. Larix occidentalis seedlings do well when they are transplanted in the fall. |
| Cultivation | Larix occidentalis prefers a moist, well-draining, slightly acidic medium. Tolerates full sun but prefers partial shade. It has an expansive root system to hold such a large tree in place, needing a deep place to set its roots. |
| Pests | Dwarf mistletoe (Arceuthobium laricis) is common, one of the most damaging diseases it can contract. Needlecast (Hypodermella laricis), Quinine fungus (Fomitopsis officinalis), and Red ring rot (Phellinus pini) are all common but manageable conditions. Larch casebearer (Coleophora laricella) though less and less common, is a serious pest threat to larch. Western spruce budworm (Choristoneura occidentalis) is seeing a decrease in cases, but is still a serious pest threat. Larch sawfly (Pristiphora erichsonii) and Larch bud moth (Zeiraphera improbana) are not common but are damaging to the plant. |
| Habitat | Larix occidentalis grows best in deep, slightly acidic, well-draining moist soils. Prefers growing at the base of North facing sloped areas. Its thick bark and high canopy make this tree very resistant to fires, seedlings also thrive in the aftermath that follows one due to the lack of competition and the abundance of nutrients. |
| Bark/Stem Description | Larix occidentalis has thin and scaly greyish brown bark while young. When matured, Larix occidentalis has very thick bark up to 15 cm deep, plated, deeply furrowed, and reddish brown. The bark on older Larix occidentalis trees commonly reach thicknesses of 1 ft (30 cm) and excess. |
| Flower/Leaf Bud Description | Larix occidentalis leaf buds are a dark brown, generally puberulent, scale margins are erose. |
| Leaf Description | Larix occidentalis needles grow from a shoot 2-5 cm long, kneeled abaxially, with shallow convex midrib adaxially. They are pale green in colour, in clusters of 15-30 and in autumn they turn to bright yellow before falling off. |
| Flower Description | Larix occidentalis has dark reddish-brown cones that are oval when closed, and ovoid when open. Cones measure at 2-3 cm x 1.3-1.6 cm on curved stalks with scales that number at 45-55. Cones are margins entire, adaxial, surface pubescent, tipped bracts at 3mm. |
| Fruit Description | Larix occidentalis seeds have a reddish-brown body that measures roughly 3mm, with a wing that measures 6mm. |
| Colour Description | Larix occidentalis has a mostly green (needles) and reddish-brown (cones and bark) overtone to the plant. In autumn the leaves turn a bright yellow, adding a good variety of colour throughout the year. |
| Texture Description | Larix occidentalis has a mostly rough texture to it. When it is young, the needles and bark will be soft and smooth; however, that will quickly change as the plant ages. The bark will become scaly, plated, and with deep ridges (furrows). |