A coniferous tree but not evergreen, the tamarack (Larix laricina) grows up to 80 feet tall, flourishing in the frigid climates of northern North America in U.S. Department of Agriculture plant hardiness zones 2 to 8. Native Americans historically made use of its roots to bind the bark of birch trees together to create canoes. In modern times the tamarack, with its unusual needles that are shed in autumn, is used for cold-climate landscaping.
The tamarack tree thrives where the summers are cool and the winters are cold, preferring boggy areas and swamps. The trees will also obligingly grow in upland sites featuring loamy soil. Across much of its range, the tamarack is the only coniferous tree that sheds its needles.
Few trees, especially large ones, are established as far north as the tamarack can grow. Its range extends from central and northern Alaska eastward across much of Canada, as far north as the Arctic Circle. U.S. distribution includes much of New England, Upstate New York, the Great Lakes Region and isolated pockets in higher, mountainous terrain in the Appalachians. Climates warmer than those of U.S. Department of Agriculture plant hardiness zone 5 are not suitable for this species.
Spur branches, offshoots of established tree limbs, are an easily identifiable trait of a mature tamarack. Seedlings and young trees don't have them. The spur branches bear spiral-type clusters of 1-inch needles; needles are spaced every few inches on regular limbs. The three-sided needles are bluish-green until cold fall weather turns them bright shades of yellow before they fall off.
Tamarack trees can be difficult to find in nurseries. The majority of viable cultivars are dwarf forms. The tamarack does not withstand exposure to heat, humidity or pollution. It suffers from infestations of certain insects, including the larch sawfly, that can quickly defoliate it. Other tamarack insect pests include the tussock moth and the larch looper.