Friday, November 4, 2011

Garry Oak in Seward Park

Quercus garryana in Seward Park June 2011

Quercus garryana in Seward Park June 2011  

Quercus garryana in Seward Park May 2011

 Quercus garryana in Seward Park March 2011

 Quercus garryana in Seward Park October 2011

Quercus garryana in Seward Park October 2011

Seward Park contains the remnants of an oak prairie that grew along the shore of Lake Washington, a small grove of Quercus garryana (Garry Oak) which includes 2 very large trees.  Garry Oak can also be found in nearby Martha Washington Park.  These trees may have been planted by the Duwamish people as a source of acorns for food.  In Seward Park, the grove can be found on the south shore of the peninsula, not far from the eastern end of the parking lot.  Garry Oak occurs from Vancouver Island to southern California. It is found mostly west of the Cascade Range but a few populations are scattered to the east. Garry Oak habitat loss is extensive. Garry Oak woodlands and savannahs in the Willamette Valley have declined to less than 15% of their extent before European settlement. In British Columbia habitat loss exceeds 95%. Habitat loss is a result of fire suppression, altered land use, introduced non-native species & heavy grazing. Quercus garryana can reach 100 feet tall with a single trunk, or 20 feet tall with many trunks. The trunks have thick, furrowed, scaly bark. Leaves are moderately to deeply lobed and measure up to 6 inches long with 3 to 7 pinnate lobes. Garry Oak produces large acorns that measure 0.8 to 1.2 inches (2-3 cm) long and mature in a single growing season. Five hundred years is the estimated lifespan. Quercus garryana is also known at Oregon White Oak.

3 comments:

R Roush said...

Sequim, Washington has done a good job of re-introducing Garry Oaks and there are large swaths of them by Bickleton, WA.

Karen Chapman said...

Do you happen to know how well the English oak (Quercus robur)would grown in the Seattle area? I would love to plant one (I'm British and have fond memories of these beauties) but have also considered the Pin Oak (Q. palustris).

Jordan Jackson said...

Quercus robur grows well here. It is approved as a street tree by the Seattle Department of Transportation. These large trees line Rainier Avenue South.