MONTPELIER, Vt. (WCAX) – Tree experts are turning to European methods to boost greenery in the Capital City.
Most trees planted on city sidewalks exist in just a few square feet of soil. On the streets of Montpelier, trees are beginning to branch out.
The life of an urban tree is typically one of restriction. “Just the roots pretty much stay in that little bit and they’re not able to venture out and not able to the anchor well,” said Joseph Ferris with Montpelier Parks and Trees.
Most trees lining Montpelier’s Main Street have around 20 square feet to work with. That can stunt growth and lead to poor tree health. But the Capital City may have a solution. It’s called the Stockholm method.
On the surface, the design is similar to traditional planting, the tree is surrounded by a square of soil and a concrete sidewalk. But down below layers of permeable fabric stone and soil create some 200 square feet of space for growth. A channel built into the concrete filters rainwater and air to the roots.
“The tree roots are actually able to breathe and access air that way through that gravel, and then they have the nutrition and fertility they need, the space underneath, to access this structural soil,” said Ferris.
Montpelier has six trees planted using this method.
Urban and Community Forestry and the Montpelier Tree Board contributed $18,000 to plant two trees this spring, an estimated $4,800 more expensive than typical tree planting due to the Stockholm Method.
Their vision: to restore Montpelier’s tree canopy.
“To find that vision as a future we just need to look into the past,” John Snell with the Montpelier Tree Board says elm trees are scarce.
Decades ago, Dutch elm disease wiped out the massive trees shading the city’s downtown. “The problem that we ran into there was they were all the same species. And that turned out to be susceptible to one pest that killed 99.9% of them,” said Snell.
Learning from that history, the city is planting a variety of tree species using the Stockholm method.
The freeman maple and red oak that took root this year are also more tolerant to road salt. And they grow fast. Tree experts say the six Stockholm trees are already sprouting faster than standing greenery.
“They could get to the point where their canopies are touching across the street and they’re looking more like forest trees or the shady downtown,” said Ferris.
Ferris hopes to one day replace all downtown tree plantings with the Stockholm method.
Montpelier Parks and Trees also note the Stockholm Method’s potential to help with flood mitigation, a high priority for the streets that were underwater just a year ago.