Western larch: The paradox tree

Ah, autumn! It’s a time when western larch trees around Washington state turn gold and drop their needles. And that’s as it should be. What? A deciduous conifer (with needles instead of leaves)? That’s unusual. And it proves that not all conifers are ‘evergreen’ trees.

The western larch (Larix occidentalis) is a member of the Cupressaceae family, which includes cypress, arborvitae and giant sequoia, but it’s one of the few conifers anywhere with deciduous characteristics. Others are bald cyprus (found in the U.S. South), dawn redwood (the shortest of the redwoods and native to China) and Chinese swamp cypress.

fire-scarred larch
The bright yellow wood visible beneath the bark in this fire-scarred larch is filled with resin, making it very decay resistant. Photo: Van Pelt.

Robert Van Pelt, a University of Washington researcher, says western larch seems to have made several adaptations to compete in an evergreen-dominated world. For example, it has one of the fastest seedling growth rates among trees in the area. This allows it to rise above neighboring trees that would otherwise block the light it needs to thrive. With its thick, fire resistant bark, western larch is found in the central and south Cascades and into Montana. It’s also seen in southwestern Washington. These trees tend to live for 250 to 350 years, but examples of trees that are 500 to 800 years old are easily found, too, says Van Pelt.

Find out more about the trees in Washington’s forests: browse Robert Van Pelt’s two color guides to identifying old trees and forests in Washington.  You can view or download the guides in their entirety.