The challenges of greening Roncesvalles

Trees and greenery are an important community priority, for both aesthetic and environmental reasons. Urban trees provide shade, cool the air and actually consume 15 times as much carbon dioxide as the same trees in a rural setting. For these reasons, the City wants to double the urban tree canopy from the current 17 percent to 30 percent.

Tree coffinTo achieve this, the City must abandon the much-hated concrete planters (right) that imprison most Roncesvalles trees. But it is not enough to dig a hole and stick the tree in the ground, either. Trees need water, air and non-compressed soil. Without them, Toronto’s trees will continue to die within 5-10 years of life, and Toronto’s tree canopy will continue to shrink. In fact, the successful trees we do have on Roncesvalles are currently thriving thanks only to the broken sidewalks, but when they are fixed in 2009 the trees will likely suffer if we simply seal them over with new sidewalk concrete.

Soil cellsAccording to forestry guru James Urban, successful urban trees also require special planting systems to allow air and water to reach the roots and to keep the soil from compressing. In his keynote address at the City’s 2004 Tree Symposium, Urban recommended “soil cells” (left), simple structures that would support the sidewalk while preventing compression of the soil beneath. The cells would then be covered over by “unit-pavers,” in such a way as to allow water and air to reach the tree roots. Unit-pavers also allow utility companies to have easier access to their underground services, since the paver can be lifted up and then replaced, instead of the current practice where the sidewalk is jackhammered, given a temporary asphalt patch, and then permanently repaired by the City months or years later.

The City has built similar systems using a continuous soil trench that supports a concrete lid. But when more concrete is poured over top, the trees will often die for lack of water and air. The City is still exploring its options, but it is clear that a successful urban tree planting system will cost much more than the status quo. But what is the cost of replacing dead trees every 5-10 years, without ever getting a proper canopy?

Seattle SEA projectOther cities in North America are moving ahead with creative urban street greening plans. A project in Portland, Oregon recently won a national award for its innovative "Green Street." And Seattle’s Street Edge Alternatives Project (right) reduced the amount of stormwater leaving the street by 99 percent, and allowed for lush landscaping on sidewalk bumpouts.

What are your ideas for greening Roncesvalles? Please email us at info@nullroncesvallesvillage.ca, or leave a comment below.

 

 

FURTHER READING:

Ahead of the Storm – Toronto’s new action plan for climate change, which includes $24 million for tree planting, in addition to the $40 million yearly budget for the Forestry Unit.

Moving towards High-Performance Infrastructure, by Mary Vogel – an image-rich summary of some innovative sidewalk designs that combine stormwater management, greenery and urban spaces.

3 thoughts on “The challenges of greening Roncesvalles

  1. joe

    It may be interesting to see what the Bloor-Yorkville BIA is planning with that reconstruction… I keep hearing that they want all the new trees to grow large to create a more pleasant pedestrian experience with the wider sidewalks.

  2. Chris.

    After attending the “Community Consultation” at High Park Baptist Church this evening (Sept. 22) and speaking to Gord Perks, while there, we have to get back to the drawing board. The information set out above on this site is completely different from what was set out in the drawings and from what Perks said. Here are some take away points:

    1. The sidewalks will be kept the same size as they are currently; no widening of existing walks.

    2. No trees will be removed from the street; those ugly cement boxes with poor canopies will stay. Perks emphatically stressed “I am not voting for any proposal that sees those trees moved.”

    3. There will be around a hundred new trees planted on the sidewalks and these trees will take up as much of the sidewalk width as the current cement tree boxes. Unfortunately, now there will be less sidewalk space for pedestrian traffic due to the introduction of these new trees.

    4. Pavers will not be used on sidewalks as mentioned in the description above. Instead, the City officials advised that they will be pouring concrete to make the new sidewalks.

    I suggest that we have a meeting of BIA and other interested stakeholders to try to figure out why there is such a disconnect in the plans. It appears that decisions have been made that compromise the idea of “the City must abandon the much-hated concrete planters”.

    I have one final comment; of course it is important to integrate greenery into the plan for ‘renewing’ Roncesvalles. However, we all know and we expect that the City will be cognizant of the need to improve sidewalks to facilitate pedestrian traffic. As the current plan appears trees have won out at the expense of much needed space to allow pedestrian flow without having to skirt around ugly concrete boxes and squeezing beside a family with a stroller due to the fact that the trees intrude on walking space.

  3. John Bowker, RVBIA

    Just to clarify: Gord Perks has reported that he will preserve all mature trees, not all trees. Councillor Perks and I spoke specifically about this last week, and I am certain he was referring only to mature trees when describing to you how he would oppose any proposal to remove “those trees.” Preserving mature trees was also a request from the BIA, as well as from residents’ groups. Such trees cannot be replanted, and will likely require the use of a newer tree planter.

    All immature or unhealthy trees (which is most of them), however, will be replaced with new trees, planted at grade wherever possible or otherwise in a slightly-raised configuration in order to accommodate the root ball, but not in an ugly tree coffin. This will increase pedestrian space slightly.

    The plans that have been posted on the BIA website have shown the sidewalk being widened at specific locations, especially at TTC stops. Otherwise, the sidewalk will remain the same width as exists now. A very early proposal showed the sidewalk being widened by about 30 cm at points, but this proposal was dropped in March of this year, presumably in order to maintain existing room for cyclists.

    However, unit pavers are apparently no longer on the table. This is a shame, because they are said to make maintenance much easier, despite being more expensive. I am told, however, that they are not crucial for healthy trees, and that designers can ensure the trees have access to air and water through other means.

    If you would like further clarification of the proposals, or if you would like to send a comment to the BIA about this, please email us at info@nullroncesvallesvillage.ca

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