Larix occidentalis aka Western Larch

Larix occidentalis is western larch, also called western tamarack. It belongs to the pine family, Pinaceae. Its range spans western Canada and the northwestern United States. It grows from the Cascade slopes to the northern Rockies. Native stands occur in mountain valleys and on lower slopes. It often grows with other trees, sometimes in swampy ground.

This large conifer sheds its needles each year. Sources give heights of 100–180 feet [30–55 metres]. Plants For A Future gives 148 feet [45 metres]. Oregon State reports trees reaching 230 feet [70 metres]. It grows fast and outgrows most gardens. The crown is open and shaped like a pyramid. Branches spread sideways from a straight trunk. Much of the lower trunk may lack branches. Young bark is thin, scaly, and grey-brown. Older bark thickens and forms deep grooves with flat ridges. Its colour shifts toward yellow-brown or reddish brown.

Young twigs are yellow-brown and may bear fine hairs. Short, stout spur shoots cover the older twigs. Needles grow singly on new growth and in older clusters. Each cluster can hold 15–30 needles. The pale green needles turn gold before falling in autumn. One tree bears both male and female cones. Male cones are yellow or yellow-green; young female cones are red. The cones develop in spring, and wind carries the pollen. Mature cones are small, egg-shaped, and reddish brown. Their thin, woody scales have fine teeth at the tips. Pointed bracts extend beyond the scales. Seeds ripen in October.

Grow it in sun with moist soil that drains well. It suits light, sandy or loamy soils, including poor ground. It accepts acid, neutral, and mildly alkaline soil. Plants For A Future lists USDA zones 2–6. Oregon State gives hardiness to USDA zone 4. Dormant trees withstand deep cold, but British winters pose problems. Mild spells can prompt growth before late frosts strike. Cold winds can then damage the new growth. Canker is another reported problem. It tolerates strong winds but not coastal exposure.

Its size suits a large specimen planting or woodland canopy. The golden autumn needles add seasonal colour. Its strong, durable wood serves construction, posts, cabinets, and plywood. The wood also provides fuel, and the bark contains tannin. People use its gum for chewing and thickening foods. Boiled spring sap yields a sweet syrup. Historical remedies used gum on cuts and bark for coughs. These records do not establish that such treatments work. Plants For A Future lists no known hazards.