WSU Clark County Extension
PNW Plants Searchable, categorized images
              

Pin Oak

Scientific name: Quercus palustris
Taxonomy
Family:Fagaceae
Type:Deciduous tree
Native:NO
Plant Requirements
Zone:4 to 8
Sun:Full sun
Moisture:Medium
Plant Characteristics
Height:75 ft
Width:40 ft
Bloom:Spring flowers
Additional Characteristics
Trees


Fruit

Leaves


Bark
Wildlife value

Poisonous
Description Pin Oak, also called swamp oak or water oak, is a Northeast native oak that frequently grows on bottom lands or moist uplands, often on poorly drained clay soils. In the Northwest it is best known for its leaf retention during the winter months.

  Morphology:
Pin Oaks are large deciduous trees that can grow quickly to an eventual height of 75’ in a pyramidal shape with lower limbs that hang down (as opposed to Scarlet Oak limbs which point up). Conversely, the middle branches on the Pin Oak are arranged at right angle to the main stem.

It bears alternately arranged, simple leaves which are 3”-6” long, with an oval shape, with 5 to 9 bristle-tipped lobes and irregularly deep sinuses that extend nearly to the midrib. Major lobes form a U-shape, as opposed to C-shaped as with Scarlet oak. A characteristic V-shaped is noted at the base of the leaves where they attach to the stems.

During the summer the leaves are bright green above and pale beneath. In the fall the leaves turn a bronze to brilliant red color before they take on their dull tan winter color.

The fruit of this oak are the well known acorns. For this species the nuts are small (1/2” long) with a thin, saucer-like cup.

  Adaptation:
While Pin Oak likes a well drained site it can tolerate wetter sites as well. It has to have an acidic site however, as landscape trees have shown iron chlorosis when the soil pH is too high.

  Pests:
Few on the West Coast of the United States. Oak wilt is common in the Midwest.
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