Woodstock hosts test trees for potential citywide streetside use

by: Merry MacKinnon An evergreen tree native to Southern Oregon, California, and northern Mexico, this black oak – planted in a parking strip along Woodstock Boulevard – is one of 30 quercus trees planted by the city as an experiment in anticipation of climate change. With hotter summers predicted, the quercus, an evergreen, would likely adapt. The question is, will it also survive Portland’s cold, wet winters?

Nothing about some new trees in Woodstock would indicate they're different from any other recently planted - just staked street trees.

But the black oak ('quercus') saplings along Woodstock Boulevard are experimental.

If they take root, and endure through Portland's cold wet winters, then the City of Portland will add the species - an evergreen, native to Southern Oregon, to California, and to northern Mexico - to a list of desirable trees that would likely adapt to hotter, drier summers that some are predicting in expectation of climate change.

'We're hopeful the trees do get established,' says the Bureau of Environmental Service's Jennifer Karps about the black oaks, planted in the parking strips between S.E. 56th and 68th Avenues. 'If they do, we will introduce more of them.'

As Coordinator of Portland's 'Grey to Green Urban Tree Canopy Program', Karps' goal is to increase the number of street trees overall. In partnership with Friends of Trees, BES promotes the planting of a variety of street trees in parking strips.

Trees not only cool down streets during hot summers, but also mitigate what happens here in winter, when rainfall turns into polluted runoff, overwhelming storm-water systems and tainting streams like Johnson Creek and Crystal Springs Creek.

Though it's speculation, Karps guesses that, depending on the species, a mature tree might sequester 500 gallons of water each year, thereby reducing the runoff that flows into storm-water drains. (For comparison, according to U.S. Geological Survey, 30 gallons of water is the amount typically used in taking a shower.)

A 2007 Portland Parks and Recreation study cited by Karps found that Portland's empty parking strips could provide enough space to double the amount of currently existing street trees. But to do that, the city has to convince homeowners to plant more street trees. 'Our charge is to expand green storm-water management,' Karps explained.

To further that effort, BES has hired canvassers to assess the potential for placement of street trees in parking strips throughout Southeast Portland and beyond, and to inform adjacent homeowners when their parking strips have room for a tree. 'This is a five-year effort - to have the area east of the Willamette River mapped for potential tree planting places in parking strips,' Karps commented.

'Grey to Green' program canvassers, wearing orange vests - like Charlie Higgins and Gerald McGarvey, who recently collected data in Woodstock - assess how wide parking strips are, as well as where street lights, poles, and water and gas lines are.

If a parking strip is suitable for a street tree, then canvassers also inform homeowners about the kinds of trees that could be planted there. 'It should be the right tree in the right place,' observed Higgins, explaining that, sometimes, on their own, homeowners unwittingly plant trees next to water meters, and then get angry when its roots break the meters or puncture their water line.

When a homeowner decides to plant a tree through the 'Grey to Green' program, the appropriate tree will depend on the parking strip size and what utility lines, if any, are overhead or underneath. 'We want to encourage homeowners to plant a tree that isn't too big or too small for the space,' Karps explained. 'And where possible, it's better to plant a native tree and - even better - to plant a native evergreen.'

After the tree is selected, BES' partner, Friends of Trees, digs the hole, plants the tree, stakes and mulches it, and then gives advice on watering and other care. Under the 'Grey to Green' initiative, approximately 10,200 trees have been planted so far, said Teri Ruch, Communications Director for Friends of Trees.

Homeowners pay for their trees, which range from a subsidized $35 to $75 per tree, depending upon neighborhood. For instance, the price for a 'Grey to Green' tree planted by Friends of Trees in the Brooklyn, Brentwood-Darlington, Lents, Powellhurst-Gilbert, Creston-Kenilworth, and Foster-Powell neighborhoods is $35. The cost is $50 in Woodstock and Sellwood-Westmoreland, and $75 in Reed and Eastmoreland.

'It's a great deal for everyone,' Ruch remarked, adding that residents in the Mt. Scott-Arleta neighborhood will receive free street trees this season.

For more information on obtaining a 'Grey to Green' tree, contact Friends of Trees at 503/282-8846, extension 16. For Spanish-speakers, the extension to ask for is 22.