What’s up with Bank Street trees

Tree planted in “structural soil medium” showing electrical cables
Photo: Jennifer Humphries

What’s up with Bank Street trees?

By Della Wilkinson

Tree-loving members of our community have been reaching out to wonder about recent work on Bank Street trees, and they provided photo evidence to illustrate their concerns.

Some photos showed trees with trunks wrapped in burlap and roots planted in what appears to be gravel; others showed electric wire wrapped around the trunks. One resident described a tree near Abbotsford House where the root ball had been placed directly on a cement platform. What is going on? Are city foresters and contractors wasting time and money on an apparently doomed-to-fail replanting strategy?

Councillor Shawn Menard’s office kindly organized a walking tour of Bank Street trees with people working on the project so we could get some answers. The “Bank Street Concrete Tree Well Cover Replacement” project involves removing the original concrete wells that had degraded and installing larger concrete wells that will give trees more space to grow. In addition, the concrete wells keep the sidewalk surface level and accessible for people with mobility challenges. When we met Menard, city staff and contractors on a sunny fall afternoon, this is what we learned.

Of the 48 trees planted when Bank Street was upgraded in 2012, 38 trees miraculously managed to grow. The remaining 10 trees died, and they are being replaced along with the concrete wells at all 48 planting sites. Clearly, the street presents a lot of challenges for growing trees. There is snow and salt to contend with. In the limited growing space, roots compete with utilities under the street and sidewalk, and the canopy competes with lampposts and wires. As a former dog owner, I learned that dog urine negatively impacts the health of trees. The chemicals soak into the bark, eventually damaging the tissue (cambium) that is responsible for transporting nutrients and water from the roots to the canopy.

What’s up, we asked, with the strange planting conditions? City forester Julie Jackson explained that the planting material is not soil but a “structural soil medium” that is designed to support the hard landscaping of the sidewalks while allowing the roots to grow through it. The medium is a mix of gravel and soil. Bank Street trees don’t get sufficient hydration from rainwater, which is directed into drains by the surrounding sidewalk, so contractors water them each week.

Moving on, we learned that the electrical cables are for uplighting and were included in the 2012 redesign at the request of the Bank Street BIA (Business Improvement Area). As the trees grow, there will be less space to support these electrical conduits, and some are being removed during the current work.

Finally, that little tree planted outside of Abbotsford on a concrete slab – everyone acknowledged that this tree will not live long as its planting site coincides with a utility pipe. Sadly, moving the site was not included in the current project.

Just under half of the surviving 38 trees are native to North America. They include Honey locust (8), Northern red oak (1), Hackberry (4) and American elm (4). The remainder are non-native trees such as Ginkgo (4), Prospector elm (14) and Japanese lilac (4).

The 10 dead or dying trees included four elms, a Gingko, a Hackberry, a Japanese lilac and three unknown species. Only one native Hackberry tree has been replanted; the rest are being replaced by non-native Japanese lilac (5), Gingko (3) and a Prospector elm (1). The city forester explained that tree selection is based on the site conditions and incorporates native trees when the site is suitable. The new Hackberry tree has been planted at the corner of Second Avenue and Bank since that site does not have overhead wires to constrict the canopy.

City staff acknowledged that the growth of Bank Street trees will be stunted compared to those planted in more suitable environments. I have long been frustrated by the drawings from planners which show large, thriving canopy trees within streetscapes when it is obvious trees cannot grow like that. This greenwashing seems to be an acceptable practice in urban design and planning, but I argue that it undermines public confidence in the project approval process. We expect outcomes to reflect the design and when we see dying trees where flourishing canopies were promised, our trust is eroded.

Although canopy trees won’t provide meaningful shade on Bank Street, we can request a Trees in Trust tree for your front yard to help maintain our tree-lined streets and avenues. To request a tree for your front yard visit: https://ottawa.ca/en/living-ottawa/environment-conservation-and-climate/public-spaces-and-environmental-programs/tree-planting/trees-trust.

Della Wilkinson is chair of the Glebe Community Association Environment Committee.