The Toronto Tree Thread

[Michael Sgambelluri]

Hello,

First post here. I joined because I have some photos to share and don't know anyone in "the real world" that has my nerdy appreciation of tree taxonomy. So, hopefully you''ll find this interesting.

Ohio Buckeye (Aesculus Glabra) is a tree native to the Carolinian forest region of Ontario, but apparently only on Walpole Island near Lake St. Clair. In Toronto, Ohio Buckeye is occasionally planted as a street tree or in parks, but hasn't been known to grow naturally in any of our green-spaces. Interestingly though, while taking a stroll down the west side of the Humber River in Etobicoke yesterday, I was pleasantly surprised to see a stand of Ohio Buckeyes growing just off the banks of the river. You can be the judge for yourself, but they don't look planted in my opinion.



It has a palmately compound leaf and a lovely sprig of flowers that sort of look like a white candle when they're mature.

 

[Midtown Urbanist]

I was reading a bit about how trees use their extensive root system to anchor them in place during particular rough weather and summer storms, and that this is why street trees sometimes topple over during the most severe of storms, because their roots are constrained by hard surfaces and smaller growing area, and therefore are unable to go as deep or as wide as they otherwise want.

It got me wondering if whether silva cells (or some other method) aid in anchoring the trees in place during those 1-in-10 year storms? (Also considering that trees will have to weather dozens of such storms over their lifespan, I don't think it's an unimportant question)

 

[Northern Light]

Hello,

First post here. I joined because I have some photos to share and don't know anyone in "the real world" that has my nerdy appreciation of tree taxonomy. So, hopefully you''ll find this interesting.

Ohio Buckeye (Aesculus Glabra) is a tree native to the Carolinian forest region of Ontario, but apparently only on Walpole Island near Lake St. Clair. In Toronto, Ohio Buckeye is occasionally planted as a street tree or in parks, but hasn't been known to grow naturally in any of our green-spaces. Interestingly though, while taking a stroll down the west side of the Humber River in Etobicoke yesterday, I was pleasantly surprised to see a stand of Ohio Buckeyes growing just off the banks of the river. You can be the judge for yourself, but they don't look planted in my opinion.

View attachment 248890View attachment 248891View attachment 248892View attachment 248893View attachment 248894View attachment 248895View attachment 248896View attachment 248897View attachment 248898

It has a palmately compound leaf and a lovely sprig of flowers that sort of look like a white candle when they're mature.

Don't know why, but I missed this post.

I can't tell anything about the provenance of the trees by looking at the leaves/canopy (nice shots though).

I would need to see the context.

If you can tell me where you saw these trees (the west bank of the Humber is several km long!).....I may be able to tell you.

But in general, I can tell you I haven't seen this species regenerating in Toronto; but that doesn't mean that it does not, only that it isn't common.

 

[Northern Light]

I was reading a bit about how trees use their extensive root system to anchor them in place during particular rough weather and summer storms, and that this is why street trees sometimes topple over during the most severe of storms, because their roots are constrained by hard surfaces and smaller growing area, and therefore are unable to go as deep or as wide as they otherwise want.

It got me wondering if whether silva cells (or some other method) aid in anchoring the trees in place during those 1-in-10 year storms? (Also considering that trees will have to weather dozens of such storms over their lifespan, I don't think it's an unimportant question)

To understand tree root typology, I like this diagram:

The above comes from:

The Tree and The Soil

Stability of the tree is really about its ability to grow its roots as wide and deep as possible.

In the case of non-tap root species, the rule of thumb is that the tree roots should be as wide as the crown of the tree.

So if you measure from the furthest out leaf, the root should ideally have reached that far in the ground.

Note, that can be upwards of 12m/36ft for many species.

Silva cells can help a bit by reducing compaction related containment; but they alone do not allow tree roots to grow, even to their own width.

The roots need moisture; so you need points of permeability that let moisture below the sidewalk to promote such growth.

Likewise, they need nutrients.

On a forest floor, you get all the decay from dead leaves, grasses, sedges, animals, insects and their feces contributing to nutrient load.

When that either doesn't exist, or is blocked from soil by a concrete cap, you're going to reduce root spread and quality.

So silva cells help.

But the biggest thing in putting trees in open-soil trenches first where they have more room, and more opportunity to access nutrients and water.

Thereafter, the ideal is permeability in sidewalks; and or finding ways to distribute nutrient-laden water, underneath same.

The tree roots don't need anything to grab onto, they just need room and good soil.

 

[kali]

Maybe this is a dumb question, but are there any tree species that have been genetically modified or artificially selected to be more resilient? Could we plant those here?

 

[Northern Light]

Maybe this is a dumb question, but are there any tree species that have been genetically modified or artificially selected to be more resilient? Could we plant those here?

No dumb questions, when they are sincere and polite as I take yours to be; its how we learn!

The answer is yes, though genetic modification through grafting/breeding as opposed to cellular in a lab.

The elm trees planted as street trees today are varietals that have above-average resistance to Dutch Elm Disease; they are typically a hybrid between our native American Elm and an East Asian cousin.

The most common maple planted as a street tree now is an Acer Freeman, which is a purposefully created cross between a silver maple and a red maple. This mix does occur in nature but this particular version gives you the hardiness of Silver Maple with Red fall foliage (silvers are natural yellows in the fall)

So there are several species that have been tweaked, and many others that are naturally quite hardy like Honey Locust; a normal Silver Maple, many different swamp species (Silver Maple is a swamp species, they tend to be able to put up with lots of abuse)

There are many species the City under-utilizes for one reason or another, most oak species are quite hardy.

However, nut-bearing species don't do as well when you plant them in the fall; which cuts back on the planting season; also the City has bad thoughts about being sued cause someone got bopped on the head by a tree nut. Truthfully, they aren't overly worried about it and are using them more, but they still under-utilize them in my opinion.

Many confiers would do well in tough conditions, provided every single dog doesn't pee on them in the first 2 years of life.

But the City again eschews conifers as street trees for a variety of reasons from wide-spreading lower branches, to less shade to fears of someone jumping out from behind one.

All rather misplaced in my judgement and nothing that couldn't be addressed by some pruning.

Cedar and White Spruce are both quite tolerant the latter abides a remarkable amount of salt too.

All that said, the best thing the City can do is create better growing conditions for trees. The larger the cubic volume of soil, the more air-exposed soil, the more complimentary species planted, in combination with proper salt management techniques, the better off the tree canopy of the City will be.

I posted some examples before of healthy street trees and will put them or others up again shortly.

PS, to anyone with a home with a street tree in front or who manages/owns a building; a reminder to water your street tree! Normally rain is fine.

But take a look at the grass and know the trees are feeling parched too!

 

[Michael Sgambelluri]

Don't know why, but I missed this post.

I can't tell anything about the provenance of the trees by looking at the leaves/canopy (nice shots though).

I would need to see the context.

If you can tell me where you saw these trees (the west bank of the Humber is several km long!).....I may be able to tell you.

But in general, I can tell you I haven't seen this species regenerating in Toronto; but that doesn't mean that it does not, only that it isn't common.

Thanks. So these were located between Home Smith Park Road and the Humber River, maybe 300 metres south of Dundas Street (could be even less than that).

I have some other shots of naturally growing sassafras and tulip tree that I'll post eventually.

 

[Northern Light]

Thought I'd share bit of a thread and link to same on abused street trees. The thread is Anne Howett's Twitter thread.

She's obsessed with (rightly) giving the City/Contractors a hard time when a tree is badly planted, or poorly maintained.

Without further ado...........lessons in how not to treat a tree!

1) Do not leave the now empty watering bag on the tree for 10 years after you plant it, risking girdling (the strangulation) of the tree!

When done w/the watering program, remove the damned bag.

2) Do not plant trees right up against a wall; not ever. But especially not a west or south-facing wall, they will get fried, in addition to crowded.

Oh, and in front of the gas connection...........not such a great location either.

3) When doing landscape maintenance; do not park your multi-ton truck right next to or under the tree compacting the soil around the roots!

4) Do not 'volcano mulch' your tree. Piling mulch high up on the tree promotes rot and does absolutely nothing to send moisture to the roots or suppress competing plants, the 2 principle purposes of using mulch.

5) Newly planted trees need watering. Older ones benefit in droughts too. But new plantings have had their roots severely cut back, they can't reach far or deep for water. So don't forget to water your damned tree for at least 1 full season after planting, 2 is even better!

6) Do not pile salt-laden snow around the base of a street tree (ahem, Bloor-Yorkville BIA)

Anne's full thread is here: https://twitter.com/rathrbinagarden

 

[Midtown Urbanist]

Planting native trees cools communities over time - REMI Network

Planting native trees, shrubs, flowers and grasses can cool the summer daytime temperature of an area by more than 4 C in a decade.

www.reminetwork.com

A new study has found that planting native trees, shrubs, flowers and grasses can cool the summer daytime temperature of an area by more than 4 C in a decade.

“We found a decrease of 4.5 C in summer daytime temperatures over 12 years and we found that this change was dependent on biodiversity,” said Jonas Hamberg, PhD candidate at Waterloo’s School of Environment Resources and Sustainability and lead researcher on the study.

 

[Northern Light]

Planting native trees cools communities over time - REMI Network

Planting native trees, shrubs, flowers and grasses can cool the summer daytime temperature of an area by more than 4 C in a decade.

www.reminetwork.com

A new study has found that planting native trees, shrubs, flowers and grasses can cool the summer daytime temperature of an area by more than 4 C in a decade.

“We found a decrease of 4.5 C in summer daytime temperatures over 12 years and we found that this change was dependent on biodiversity,” said Jonas Hamberg, PhD candidate at Waterloo’s School of Environment Resources and Sustainability and lead researcher on the study.

I read the abstract; might need to renew my U of T alumni/library card for access to the underlying article/study.

No question that restoration vs pavement/hardscape, or mowed lawn can produce substantial temperature benefits.

I'm not sure about diversity unto itself; and would be interested to see the research.

Certainly, tall grasses, in addition to the shade of trees and shrubs make sense.

Beyond that, I need to look into this further.

 

[Michael Sgambelluri]

Tulip Tree is a Carolinian indicator species that reaches the northern limits of its range in Toronto. Although it's planted widely as a street tree, it also grows in the wild in a few spots, such as the Yellow Creek ravine, Toronto Island, and where the below shots were taken, along the eastern side of Etobicoke Creek just north of Marie Curtis Park. It may grow elsewhere in the city, but these are the locations that I'm aware of.



Know as tulip tree because of its tulip shaped leaf, but also for its beautiful tulip-like yellow-orange flowers that blossoms in June and early July. Unfortunately, I think due to the cold snap back in early and mid May there aren't many flowers this season. One of my favourite trees.

 

[Northern Light]

Tulip Tree is a Carolinian indicator species that reaches the northern limits of its range in Toronto. Although it's planted widely as a street tree, it also grows in the wild in a few spots, such as the Yellow Creek ravine, Toronto Island, and where the below shots were taken, along the eastern side of Etobicoke Creek just north of Marie Curtis Park. It may grow elsewhere in the city, but these are the locations that I'm aware of.

View attachment 259174View attachment 259176View attachment 259175View attachment 259177View attachment 259178View attachment 259179View attachment 259180View attachment 259181View attachment 259187View attachment 259186View attachment 259185View attachment 259183View attachment 259182View attachment 259181

Know as tulip tree because of its tulip shaped leaf, but also for its beautiful tulip-like yellow-orange flowers that blossoms in June and early July. Unfortunately, I think due to the cold snap back in early and mid May there aren't many flowers this season. One of my favourite trees.

Tulip tree generally performs very poorly as a street tree.

I've seen a very high percentage die (over 70%).

Tulip trees are extremely salt intolerant.

I don't know what possessed the City to plant them in grade-level boulevards on major roads.

Poor choice.

In above-grade planters, set back at least 1M from the curb they might do OK, I'm not certain how many the City has tried in those conditions.

Planted in quality soil, away from significant salt spray they may do quite well here. I've seen many excellent specimens.

Though, being as this is really (slightly) beyond their northern range, in my experience they do better in sheltered conditions (ie. not subject to high winds). (trees feel wind chill too!)

I find they perform best in large court yards (in softscape); Backyards surrounded by other large trees, large front yards, setback more than 2M from the sidewalk; and natural parks.

 

[Michael Sgambelluri]

Tulip tree generally performs very poorly as a street tree.

I've seen a very high percentage die (over 70%).

Tulip trees are extremely salt intolerant.

I don't know what possessed the City to plant them in grade-level boulevards on major roads.

Poor choice.

In above-grade planters, set back at least 1M from the curb they might do OK, I'm not certain how many the City has tried in those conditions.

Planted in quality soil, away from significant salt spray they may do quite well here. I've seen many excellent specimens.

Though, being as this is really (slightly) beyond their northern range, in my experience they do better in sheltered conditions (ie. not subject to high winds). (trees feel wind chill too!)

I find they perform best in large court yards (in softscape); Backyards surrounded by other large trees, large front yards, setback more than 2M from the sidewalk; and natural parks.

Interesting. They're fairly commonly planted as a street tree so that is strange. I'd be nice to see a numerical breakdown though I don't think the City keeps that, but I'd say there's a least one on every other street here in my little slice of Etobicokian suburbia. I'll keep a keener eye on them to see if they look stressed. Now that you mention it, some of the more prodigious examples of tulip trees I've seen in Toronto have been in park meadows or in the wild.

 

[Northern Light]

Interesting. They're fairly commonly planted as a street tree so that is strange. I'd be nice to see a numerical breakdown though I don't think the City keeps that, but I'd say there's a least one on every other street here in my little slice of Etobicokian suburbia. I'll keep a keener eye on them to see if they look stressed. Now that you mention it, some of the more prodigious examples of tulip trees I've seen in Toronto have been in park meadows or in the wild.

The key is salt spray. So on a low volume road and/or one with a wide boulevard where the tree is set well back (I'm thinking sections of Eglinton West), they should be fine.

Busy street, close to the curb, very high mortality.

Now, some may luck out, if the melt water pools well away from them, or they are just a hardy individual (non-cloned trees show variation in their range of tolerances) they might just make it.

I'd personally prefer the City stuck to pure natives; but if we stretch the definition to something might be native in Niagara or Windsor etc...

I think Kentucky Coffee Tree has a much better track record for survival.

Though there is some risk it may be invasive (I've seen it reproducing in ravines); now its near-native....is that the same problem as Norway Maple? No.

On the other hand I'd rather support the full diversity of what does belong here.

 

[yrt+viva=1system]

Thought I'd share bit of a thread and link to same on abused street trees. The thread is Anne Howett's Twitter thread.

She's obsessed with (rightly) giving the City/Contractors a hard time when a tree is badly planted, or poorly maintained.

Without further ado...........lessons in how not to treat a tree!

1) Do not leave the now empty watering bag on the tree for 10 years after you plant it, risking girdling (the strangulation) of the tree!

When done w/the watering program, remove the damned bag.


View attachment 257634

I have never once seen the city fill up these water bags! They went on a blitz installing them but never filled them up unlike other jurisdictions. Got to wonder how much they costed the city before they were removed.