WSU Clark County Extension

PNW Plants Searchable, categorized images
              

Douglas Fir

Scientific name: Pseudotsuga menziesii

Taxonomy
Family:Pinaceae
Type:Coniferous trees
Native:YES
Plant Requirements
Zone:5 to 8
Sun:Full sun
Moisture:Dry
Plant Characteristics
Height:200 ft
Width:30 ft
Bloom:Spring flowers
Bloom Time:April to May
Bloom Color:Red
Additional Characteristics
Trees


Fruit

Leaves


Bark
Wildlife value

Poisonous
Description Douglas-fir is one of the world's most important and valuable timber trees. Its range is from northern Vancouver Island south to the Santa Cruz Mountains west of the San Francisco Bay region.

  Morphology:
As a Northwest evergreen, this tree can grow to a prodigious height of over 250’ on undisturbed woodland sites. East of the Cascades, Douglas fir typically grows to a mature height of 125’. At maturity trees can grow to 30’ wide.

The shape is classified as pyramidal with a somewhat open stature. On mature trees the lower branches droop while the upper branches point upward.

Needles are 1.5” long and flattened in cross section. On the branches they are arranged radially.

This is a monoecious species. Male cones are oblong, red to yellow, and appear near the branch tips. Female cones hang from the branches and are 3” to 4” long. The edges of the scales on the cones are rounded. Three-lobed bracts extend beyond the cone scales and resemble mouse tails. The cones are mature by the end of the summer, at which time seed can be collected to start new trees.

As for the bark, young trees are smooth and gray in color. Older trees have a very thick bark which is red-brown with ridges and deep furrows.

  Adaptation:
Douglas-fir reaches its best growth on well-aerated, deep soils with a pH range from 5 to 6. It will not thrive on poorly drained or compacted soils.

  Pests:
Root rot is problem on poorly drained sites.
For assistance, contact Dr. Charles Brun (brunc@wsu.edu), (360) 397-6060 5701
Computing and Web Resources, PO Box 6234, Washington State University, Pullman WA 99164-6234