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City of (Mulched) Trees

Most of the trees lining the north side of Idaho Street from Fifth Street to Capitol Boulevard will be torn out for new sidewalks.


One hundred trees throughout Boise's downtown now have public notice signs nailed to their bark.

"This tree is to be removed after ___ days for the following reason," the signs read.

The reasons, written in Sharpie, range from "Construction" to "CCDC Streetscape Project."

Most of the trees lining the north side of Idaho Street from Fifth Street to Capitol Boulevard will be torn out for new sidewalks. That's not a bad thing, according to City Forester Brian Jorgenson, adding that the new sidewalks will be more "tree-friendly," explaining that the new sidewalks will be built on top of Silva Cells, which are basically big boxes of soil allowing large trees to grow and roots to spread. The sidewalk is then suspended above the soil. Right now, trees in the sidewalk survive in small boxes that compromise their roots. Jorgenson said the Silva Cells also manage stormwater more effectively.

"I've wanted to try this in Boise for 10 years," Jorgenson said. "I'm happy to see we're making progress in that way. It'll make for a healthier downtown."

The trees that work crews will remove from the sidewalks can't be replanted though, either because they're too large or their roots are too gnarled from the confined soil. They'll be mulched or sold as firewood.

Boiseans will continue to see public notice signs spreading from tree to tree in downtown this summer as the sidewalks are replaced.

Jorgenson said that around 100 trees have been removed from city property since October 2014. He has a strict replant rule, though. For every one tree removed, he strives to plant two more. So far, 220 trees have been planted.

Trees aren't only being removed from downtown's streets. There are 30 trees slated for removal between Capitol Boulevard and the Idaho State Historical Museum to make way for the museum's 15,000-foot expansion.

The trees are around 40 or 50 years old, according to an estimate by Jorgenson. Idaho State Historical Society Executive Director Janet Gallimore said the decision to remove so many trees wasn't made lightly.

"We don't take down trees in a non-thoughtful way," Gallimore said. She said many of the trees being removed have reached the end of their lifespan and needed to come out anyway.

She's worked with the architects of the project to protect some of the older oak trees next to the pioneer village.

"We changed the building design to work around [the trees]," she said.

In order to preserve the oak tree, construction crews have to be careful not to disturb it during the renovation and re-landscaping.

Toby Norton is the parks resource planning manager for the city, and the landscape planner for the museum's facelift. He told BW that the oak tree will be fenced off to keep construction crews from parking too close or storing equipment beside it. He said it's important to keep the critical root zone intact.

"We have literally moved buildings to save some of the trees that are there," Norton said. "Anything we can do to help those trees stay healthy during construction."

Norton and Gallimore are still at the drawing board for new landscape designs, but Norton said the grassy berm separating the sidewalk and the museum will now be leveled. The sidewalk will be offset from Capitol Boulevard and the grounds of the museum will incorporate more plants from the pioneer village area.

"It's going to be a really nice landscape design," Norton said. "There was a strong effort to tie the inside of the museum to the outside grounds. The plants will pick up themes that are going on inside and bring them out."

Gallimore estimates the museum will be complete and open again between the summer and winter of 2017. She acknowledged that a green footprint is important to the city, and said the new design will provide more shade in different areas.

As for the 30 that will be torn out for the landscape redesign, they'll be mulched or sold as firewood. Despite those and other trees being removed from Boise's downtown core, Norton insists the practice is done sustainably.

"We're not in the business of removing trees," he said. "We do what we can to save trees and replace and mitigate for the ones that do get removed."

Beyond the Parks Department's mission to plant two new trees for every one taken down, other programs exist to fill out the Treasure Valley canopy, including residential tree giveaway projects through Idaho Power and the Boise City Forestry Division.