CORVALLIS, Ore. ñ A commonly held notion is that ponderosa pine (Pinus ponderosa) is native only east of the Cascades in Oregon. As you cross Oregon's Cascade passes going east, beautiful forests are dominated in places by these majestic yellow-barked pines.
But unbeknownst to most, a form of ponderosa pine is also native to the Willamette Valley of western Oregon, explained Rick Fletcher, forester with the OSU Extension Service in Linn and Benton Counties. And it can be used as a water-wise landscape tree in your yard or garden.
"At the time of European settlement, ponderosa pine was found by Oregon's early settlers, scattered throughout the Willamette Valley, often near stream banks," said Fletcher. "Researchers now know that the Ponderosa pine found in the Willamette Valley is genetically very different from trees found in eastern Oregon.î
Historically, the natural stands of the ponderosa pine in the Willamette Valley have been significantly reduced by agriculture and development, but it is capable of growing throughout most of the Willamette Valley, said Fletcher.
In the 1970s, local foresters, nursery owners and landowners became aware that there were a few remnant native populations of the Willamette Valley ponderosa pine still remaining. They began efforts to collect cones from these stands and propagate seeds to grow plants from distribution and reestablishment.
In 1994, the Willamette Valley Ponderosa Pine Conservation Association was organized, to conserve the genetic resources of the Willamette Valley race. This nonprofit group worked with the OSU Extension Service, Oregon Department of Forestry and several private groups to carry out their program.
"The results are that the Willamette Valley form of ponderosa pine is now relatively easy to obtain," said Fletcher. "It is offered for sale by many of the Soil and Water Conservation programs in western Oregon and it readily available at native plant nurseries."
"Willamette Valley landowners today are planting more than 1 million native ponderosas each winter," said Fletcher, "and vigorous young ponderosa pine forests are once again springing up all around the valley. While they have their share of natural predators and pests, these young stands are generally doing very well."
Fletcher says that the Willamette ponderosa pine is a valuable tree for homeowners to use in plantings on drought-prone sites, and in or near wet or poorly drained areas. Because of its deep taproot and stability, it may also be suited to urban uses.
The OSU Extension Master Gardener program considers western Oregon's ponderosa pine to be a "water-wise" tree. That is, once established, it takes a minimal amount of summer watering.
When choosing a ponderosa pine for your own landscape or property, Fletcher stresses that you should make sure you get the right sources.
"If it is not labeled, it is probably the kind from drier areas of the west," he said. "That's fine if you live east of the Cascades. But if you live on the west side, you'll want to get the pines grown from native Willamette Valley seed."