Redesigning the urban forest, one neighborhood at a time



Missoula's urban tree canopy has long been dominated by the Norway maple, which settlers planted en masse in the early 20th century. The city's urban forester, Chris Boza, predicts that in years to come the valley will burst with a more expansive variety of woody greenery if the city follows through on its neighborhoods' proposals. The Riverfront Park neighborhood, for instance, would be marked by Western larch and Green Mountain maple. Sapporo autumn gold elm and cucumber magnolia might line the streets of Moose Can Gully. Rose Park's residential streets could be shadowed by Marmo maple and accolade elm.

That's just a sample of the tree palettes designed by the first neighborhoods to engage in the city's urban forest management plan, which was approved in 2015 and kicks into gear this year. Boza is also hoping the city can find a way to reduce the cost of planting nearly 16,000 trees throughout Missoula over the next few decades. (Plantings are set to start in 2020.) The need is pressing: The Norway maples, which account for about 30 percent of the current canopy, are reaching the end of their century-long lifespan, and most will die within a few decades. Missoula's urban forest is valued at $89 million.

"It's a fairly large chunk of change," Boza says. This winter, he's been conducting an experiment to see if the city can grow its own saplings, instead of buying them on the open market. A dozen young Marmo Freeman maples and northern catalpas are wintering in a small gravel-bed nursery near the municipal wastewater treatment plant. Boza is optimistic they'll survive and grow large enough to be transplanted to their final destinations. The city's Public Works department is also looking into purchasing a few acres next to the Garden City Compost site, which might provide fertile ground for a city-run nursery.

Boza says tree cultivars from commercial nurseries cost about $150 apiece. He estimates that it would cost the city about $45 to grow them locally. Martin says it's also possible to grow trees on site from seed, but that can lead to problems down the road if the tree turns out to have undesirable traits. Female gingko trees, for instance, produce stinky cones that, Boza says, smell like "cat manure and beer and pizza vomit."

In the early 1900s, settlers planted Norway maples throughout Missoula. As those maples die off, the city is redesigning its urban forest to be more diverse. - PHOTO COURTESY KELLEY HIRNING
  • photo courtesy Kelley Hirning
  • In the early 1900s, settlers planted Norway maples throughout Missoula. As those maples die off, the city is redesigning its urban forest to be more diverse.

"So that's an instance where if you buy a cultivar, it's a male cultivar," he says.

It's up to each neighborhood to form a leadership team to choose from almost 140 approved species to create an individual neighborhood tree palette. In the Southgate Triangle neighborhood, longtime resident Bob Martin has led the charge. Southgate's palette includes scarlet oak, ponderosa pine, sugar maple and purple beech.

Martin has learned that those choices can be controversial, even though the planting palettes are only recommendations.

"I know there's been some backlash from people doing landscaping who say, 'I'll go out and stick any god-dang tree in the ground I want,'" Martin says. "Which is fine, but I'd rather see diversity, instead of the guy who gets a good deal on 200 of any particular tree."

Six of the city's oldest and most heavily vegetated neighborhoods have produced tree plans so far. Most of the city's newer and less densely planted neighborhoods, like Lewis and Clark, have yet to sign on. Martin has observed that the most active neighborhood groups are led by retired people with more time to devote to civic engagement.

Urban trees have proven benefits when it comes to neighborhood livability, crime reduction, noise absorption, walkability and biodiversity. And while Martin hopes that more neighborhoods will get involved, he acknowledges that tree selection can feel like a weighty decision, considering that trees planted now will help define the city's character for generations to come.

"We're hoping people will look online for our forestry plan and choose trees around that list," Martin says. "I just want to see trees getting planted."

Once the planting program begins in 2020, the city plans to evaluate its progress every five years. The last of the Norway maples should be removed by 2035.

Forest plan information is available at


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