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Saturday - November 20, 2010

From: Seattle, WA
Region: Northwest
Topic: Privacy Screening
Title: Large evergreens for screen in Seattle
Answered by: Nan Hampton


Our building would like large evergreens to help with freeway noise (it's right across the street with a large green belt around it.) Which Northwest Evergreens would work best? We need tall and wide ones being that it is a very big area to cover. Thanks!


Why not use the Washington State Tree, Tsuga heterophylla (Western hemlock)?  It grows to 100 feet high in cultivation and nearly twice that tall in nature.   It has a graceful appearance with drooping branches and grows in variety of soils but likes humid or superhumid climatic conditions with adequate soil moisture.  Read more about it from the U. S. Forest Service and see photos and more information from Washington State Department of Natural Resources.

Another possibility is Pseudotsuga menziesii (Douglas fir), the Oregon State Tree.  It grows to around 200 feet, but landscape trees grow only to about 80 feet tall and 15 to 20 wide.  If it is growing alone or widely spaced from other trees, it usually retains its lower limbs.  If crowded, it may lose the lower limbs, exposing the trunk.  You can read about the tree and see more photos from the Washington State Department of Natural Resources.  See, also, the University of Connecticul Horticulture site for more information.

Thuja plicata (Western red cedar) is another large (typically up to 75 feet, but can grow to 200 feet or more) evergreen that usually retains its lower branches. It is more decay resistant than the Western hemlock or the Douglas fir.  There are photos and more information from Washington State Department of Natural Resources and from Conifers.org.

Finally, there is Picea sitchensis (Sitka spruce) that prefers coastal areas but will grow inland in well watered soils such as river flood plains.  Here are photos and more information from Washington State Department of Natural Resources and Conifers.org.

Here are photos of the Douglas fir from our Image Gallery:

Pseudotsuga menziesii

Pseudotsuga menziesii

Pseudotsuga menziesii



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