The Trees Must Be Crazy

Fall has finally fallen here in the Northeast, at least for a few days. In parts of the Northwest, it may already seem like a distant memory as an early winter is settling over the Cascades. Seasonally, despite the wacky weather, it is a perfect segue into this week’s Nature Minute: the odd foliage of the Pacific Northwest.

Everyone knows the old line about deciduous trees ending chlorophyll production in the fall. We see the leaves change colors and drop off annually. Also, you know that evergreen trees keep their green needles year-round. They actually shed needles constantly, but stay with me here! What if I told you that in the forests of Washington, some of the trees have it all mixed up?

In areas less than 50 miles or so from the Pacific coast, there is a deciduous tree called the Pacific madrone or madrona tree. It has thick leathery leaves, and it keeps them all year. Unlike the maples, oaks, cottonwoods, and alders of the Northwest that go bald every year by November, the madron sheds its leaves every other year.

Pacific madrone

Leathery leaves of the Pacific madrone

Unripe berries of the Pacific madrone. The berries will ripen in fall and winter,
providing a much-needed food source for birds and other critters.

Another tree that defies the consensus is the larch, a conifer found on the east slope of the Cascades. Like its friends the firs, spruces, and pines, the larch has needles on its branches. However, once fall arrives, the larch’s needles turn golden yellow and fall off. That’s right, the Northwest has an evergreen deciduous tree and a deciduous conifer. Now that everything you know is wrong, the big question is why. The easy answer is that no one knows. But fall is a great time to curl up with a mystery.

Summer larch (British Columbia Ministry of Forestry photo)

Fall larch (Herb Museum photo)