Differences Between Coastal Redwood and Douglas Fir Trees

Hiking through the coastal redwood forests in Northern California, visitors will be greeted by towering conifers. The tallest trees in the world, coastal redwoods (Sequoia sempervirens) make up a dominant part of the tree species in the ecoregion. Co-occurring with coastal redwoods in this region of the world are Coast Douglas-fir trees (Pseudotsuga menziesii var. menziesii).

What is the coastal redwood forest ecoregion?

The coastal redwood forests extend along the Pacific coast from southern Oregon to central California, with the densest concentrations in Northern California. This narrow belt of redwood trees is situated within the coastal climate zone, usually within 50 miles of the coast.

The region experiences a Mediterranean climate with wet, mild winters and dry summers. Coastal fog, which moves inland from the Pacific Ocean, provides essential moisture during the dry season.

Dominated by the coastal redwood (Sequoia sempervirens), these forests also contain a variety of other trees, such as coast Douglas-fir, western hemlock, and tanoak. The understory is ferns, shrubs, and a diverse array of mosses and lichens.

Range of the coastal redwood tree

Range of the coast Douglas-fir tree

Douglas-fir trees are common across western North America. The coast Douglas-fir range spans from central British Columbia down to central California, covering over 1,367 miles. In the north, its distribution is limited by temperature, while in the south, moisture is the limiting factor. Coast Douglas-fir extend further inland than that of the coastal redwood range.

The Coast Douglas-fir variety thrives in the maritime climate of coastal areas, with mild, wet winters and dry summers, as well as in the montane habitats of the Cascades and Sierra Nevada, which have colder winters, shorter frost-free periods, and a wide range of seasonal temperatures.

How to tell coastal redwood and Douglas-fir trees apart

With the coastal redwood being the tallest tree in the world, and the Douglas-fir being among the tallest tree species, both of these conifers are a towering presence in the forest. Mature coastal redwoods (Sequoia sempervirens) typically reach heights between 300 to 350 feet.

There are two varieties of Douglas-fir: the coast Douglas-fir, found in the Pacific Northwest and California, and the Rocky Mountain Douglas-fir, found in the interior west. The coast Douglas-fir (Pseudotsuga menziesii menziesii) is the taller of the two varieties, commonly reaches heights of 250 feet and can grow to well over 300 feet tall. In a forest with varying ages of both species, you can’t rely on simply tree height to determine which is which.

There are three aspects of coastal redwood and Douglas-fir trees you can focus on to learn how to tell the two tree species apart: bark, needles, and cones.

Needles: coastal redwood versus Douglas-fir trees

The needles produced by coastal redwood trees are distinctly different than Douglas-fir trees.

Coastal redwood needles

Coastal redwood needles are flat, slender, and arranged in a single plane along the branch, giving the branches a feather-like appearance.

Coast Douglas-fir needles

Coast Douglas-fir needles grow in a spiral around each branch, making the branches appear fuller.  The pattern of the needles is similar to a bottle brush. The ends of the coast Douglas-fir needles are more pointed than those of coastal redwood trees.

Coastal redwood bark

Coastal redwoods have thick, fibrous bark. This bark can grow over 12 inches thick with deep vertical grooves. This bark offers protection against fire and insect damage. Looking close up at trunk of a coastal redwood tree, the bark has a reddish-brown tint that gives these tree species their iconic name. The bark is also very fibrous, with hairy strands.

Coast Douglas-fir bark

Coast Douglas-fir bark also has vertical grooves but the bark is not as thick. Coast Douglas-fir bark is typically between 4-12 inches thick. The bark is a grayish color.

Cones: Coast redwood versus coast Douglas-fir trees

Coast redwood cones are small, about an inch long, and have a wrinkled, woody texture. In contrast, coast Douglas-fir cones are larger, ranging from 2 to 4 inches in length, and feature distinctive three-pronged bracts that protrude from between the scales.

References

Coastal redwood and Coast Douglas-fir range maps based on data from: Little, Elbert L., Jr. 1971. Atlas of United States trees. Volume 1. Conifers and important hardwoods. Miscellaneous Publication 1146. Washington, DC: U.S. Department of Agriculture, Forest Service. 9 p., illus. [313 maps, folio].