By: Guelph Mercury
Planting a tree in an urban environment is like placing it on death row.
In the wild, ash and linden trees can live anywhere from 80 years to more than 200, says Martin Neumann, manager of the City of Guelph’s forestry department. But once that same type of tree is planted along a street in a city’s downtown, the average life expectancy of that tree is cut to seven years.
Last year, around 25 ash and linden trees were chopped in downtown Guelph because they were dead, or close to it, Neumann said. Their stumps have been left behind, sticking out like tombstones along the sidewalks, the tree rings telling the stories of their short lives.
This spring, 13 trees will be cut down along Carden Street for the same reason. Although some of these trees are ash, the emerald ash borer isn’t being handed the blame for their death, Neumann said. “(The ash borer) was just arriving while the tree was already declining.”
Guelph is not unique in its treatment of trees growing downtown. Trees growing in the heart of any city across the country face the same type of hardships, Neumann said. “Every possible thing we could do to make life hard for them, we’ve done.”
The soil conditions are not nearly as good as it would be out in the forest. Growing next to city streets, urban trees get loaded with salt every winter and cigarette butts seem to pile at the base of their trunks. Urban areas also seem to experience moisture and climatic extremes throughout the year, more than rural areas, Neumann said. The trees have a hard time dealing with really hot summers and really cold winters.
The city is now working on a plan to reintroduce the trees that were lost, but the planning is still in its early stages. Neumann said the reintroduction will have to coincide with any downtown renewal plans and sidewalk repair plans. “We have to try to make sure we’re not planting a tree just before somebody’s going to rip up the street.”
The 13 trees that were removed along Carden Street are expected to be replaced this summer with Freeman maple trees, he said. The Freeman maple is a big tree. If it grows beyond the seven-year average, it may end up taller than two or three storeys.
With the help of new technologies and a little more tender love and care, the city expects these replacement trees to live for much longer than seven years, Neumann said. “We’re going to invest in their maintenance with that mindset.” He said they probably won’t live for 200 years downtown, but maybe they could reach 30 or even 50.
In the past, trees were placed into pits and were left to explore whatever nutritious soil they could find. But once the tree roots went beyond the borders of the tree pits, there was no nutrition for them to find, Neumann said.
The city will now be using soil cells instead of simply digging pits for the trees. With soil cells, soil is placed underground and divided into various levels, like a wafer. The cells can support the weight of sidewalk tiles while also enabling tree roots to expand beyond where a tree pit might allow.
The trees to be removed along Carden Street were planted with soil cells, Neumann said, but their demise was caused by a combination of other issues. The soil cells worked well, he said.
Some of the locations downtown where trees once grew will no longer be able to support another tree planted there. While the tree was alive, underground infrastructure was drilled in and placed too close to the tree, Neumann said. Replacement trees will need to be planted somewhere else.
With Wyndham, Quebec and Baker streets soon up for renewal, Neumann said, the city will hold off on planting new trees in these locations. To replace the lost trees on these streets, the city will be launching a pilot project involving trees in large planting boxes.
The proposed project is still in its infancy, he said, but is expected to kick off this summer. This project would have to be in collaboration with the downtown business association, and the two sides haven’t had a chance to connect about it yet.
Marty Williams, executive director of the Downtown Guelph Business Association, said the jury is out among the business owners on whether large, leafy trees are a positive addition to the core. While they may be beautiful and provide clean air and shade, depending on their location they could end up blocking signage and storefronts from the eyes of potential customers.
Williams said personally, he thinks trees are a positive element in any downtown core. “They’re bringing beauty, shade and colour to an otherwise concrete and asphalt environment.”
The idea of tree boxes placed around the downtown has a lot of potential, he said. If businesses have a problem with where these trees are placed, they can be relocated.
By: Guelph Mercury