If your area experiences cold winters with frequent sub-freezing temperatures, choosing a tree that's adaptable to your climate can be crucial for success. The tamarack tree (Larix laricina), also called the American or Eastern larch, is a conifer that's extra-hardy and also an attractive specimen. The tree grows in the cool climates of U.S. Department of Agriculture plant hardiness zones 2 through 5.
The tamarack tree is unusual because it's a deciduous conifer, or a cone-developing tree with needlelike foliage that it sheds each year when cold weather arrives. It's a native tree that grows wild in the forests of the northern U.S. and parts of Canada, growing as far north as regions near the Arctic Circle. In the U.S., it's often found in forested areas where rich, moist soil predominates because of nearby bogs or swamps, while it usually grows in more upland, mountainous areas in Canada.
In the Home Garden
A cultivated tamarack tree does best in regions where winters are relatively cold and periods of sub-freezing temperatures can last for several days or more. It's not an especially heat-tolerant tree and doesn't do well in areas with long, hot summers. The warmest part of its range, USDA zone 5, has only about 30 or 40 days each year when temperatures exceed 85 degrees Fahrenheit. More extensive periods of high heat can interfere with the tree's growth and ultimately damage it, so it's not a good choice in climates higher than USDA zone 5.
Selecting a Site
A tamarack tree can grow to 50 to 80 feet tall and needs a spot where it won't be crowded by other large trees. It also prefers full sun and does best where it receives bright sun for most of the day. It can tolerate a spot that tends to get wet often, provided its site is well-draining and it doesn't become waterlogged for long periods. It branches are soft and sway easily in breezes, so the tree is also a good choice for a windy spot.
The needles on the tamarack tree turn an attractive, deep yellow in fall before they drop from the tree. Because it's a tough tree and thrives in cold weather, the tree doesn't need mulching for fall protection, but adding a layer of organic mulch under the tree in spring can help conserve soil moisture during hot summer days, while also keeping weeds under control. It does best in rich, loamy soil, so adding some compost at planting to increase your soil's fertility can give a new tree a boost. If your soil is rich in clay and drains poorly, mix some sand into the planting site to improve its drainage.