I’m conflicted. Everything about the Norway maple (Acer platanoides) points to it being a blight on the landscape. It’s invasive; taking over our ravines and crowding out native species. It is not a multi-purpose tree. True – it gives shade, produces oxygen, filters the air, and mitigates stormwater. But, it doesn’t host any insect parties. From what I’ve seen, it’s only good for aphids and tar spot fungus (Rhytisma acerinum).
Why, in Canada, Norway maple has supposedly even infiltrated one of our government institutions – The Royal Canadian Mint. According to some, it’s in circulation as legal tender on our new polymer bills! This caused a big, botanical flap last year when the $20 bill was introduced and several botanists pointed out that what was supposed to be a sugar maple leaf looked more like a Norway maple. The Mint pleaded artistic license, or in this case, botanical license, saying that “the leaf is a stylized blend of different Canadian maple species”. Leaves are variable in nature, but I don’t think they look quite like either Norway or sugar maple. With so many teeth, maybe it has a touch of red maple and ?
Apparently, no one carries around a wad of $50 and $100 bills which were rolled out much earlier with the same rendition of the leaf and did not cause a flutter. I guess if you can flash that kind of cash, you won’t notice the vegetation on our only green bill and you are not employed as a botanist.
Since Norway maple is more ubiquitous than the eastern species, sugar maple, making it more representative of Canada as a whole, should we be surprised?
Maybe I shouldn’t bring it up, but those leaves on the right side look like Norway maple leaves. And the corn poppies (Papaver rhoeas) on the reverse side of the $20 bill are non-native and considered invasive in Alberta.
More evidence that the Canadian government has been invaded: the Mint started phasing out the penny. Hint: it had a sugar maple depicted on it.
I would love to get rid of the Norway maple, both on the bills and in the environment. But I’m stuck with the currency and with a behemoth…
When I first lay eyes on the tree, it was part of a package.
I wanted the bungalow and a chance to have a garden, yet this tree came with it. A mature tree is a selling feature, but for someone who recognizes it as a Norway maple and is knowledgeable about its faults…well it does take a little bloom off the rose.
How to reconcile the disappointment of not having a native tree, particularly the only large tree on your property? Learn to live with what you can’t change and make the best of it, warts and all! Many people enter into a serious relationship with the expectation that they can make drastic changes to their loved one, only to find the immovable boulder. Similarly, a large tree is a major structural element of the garden that can’t be changed and is not an accessory that can be disposed of easily when it doesn’t fit into the garden scheme or someone has grown tired or bored of its existence. Reality hits in the form of a bylaw which soon puts a stop to thoughts of removing large trees – usually. In Toronto, Chapter 813, Trees, protects all city trees and those trees on private property with a diameter at breast height (dbh) of 30 cm (12”) or greater. If it is a city tree, owned by the city and fairly healthy, no matter the size, there is no way they will remove it on a whim.
Indeed, sometimes the city goes to the extreme to keep a tree even though it is damaging a foundation. Other times, it gives the all clear to clear cut for development. In many instances, it’s all political with municipal councillors weighing in. In reality, trees are not as valued as they should be. If they were, development would be forced to accommodate existing vegetation. Now there’s a progressive concept!
As a rule of green thumb, I have suggested planting a tree at least a minimum of 3 to 4 metres (over 10’) from a house to give the tree roots room to grow. Large species, like oak, need more room. LEAF, (Local Enhancement & Appreciation of Forests) a not-for-profit organization has a guideline for requirements of backyard planting which has merit for front yards as well.
Besides large tree roots, the other hazard near structures is falling tree branches. Hazards can’t be eliminated when you live in confined areas, like small city plots which don’t have ideal conditions for city trees, i.e., which may have been planted closer to the house and now those branches overhang the house rather than just cast a shadow.
In other cases, branches falling can be totally avoided. NPWG Team Leader, Carole Sevilla Brown documented her fight with a neighbour that could have been titled: “How not to take Norway maple down safely” or “Extreme Arborism not for the faint of heart or mind”.
My Norway maple usually drops tons of keys in the spring and aphid “pee” all over the car parked on the driveway. It had dropped a couple of small branches during wind storms. One larger branch broke and dented my neighbour’s downspout disconnection and loosened the hydro lines between our houses.
The most significant branch to date fell after high winds on Friday, September 23, 2010. A neighbour phoned to inform me that a branch had dropped on my car. I called the city to report the incident and raced home from work to find a large branch adorning my car like a rack of antlers.
This was not a good situation. We had a NANPS field trip to some tallgrass prairies the next morning. We couldn’t move the branch, not because of the weight, but because we wanted the incident documented by the city when they showed up to remove it. So, while we waited, we took pictures. The wind had carried the branch far enough to hit the car, otherwise, it would have dropped straight down onto my front path and likely miss the car.
The frame at the corner of the car roof took the main brunt. There were a few scrapes and bruises to the car as the branch rolled across the hood. Fortunately, the windshield was intact.
Finally, a city crew showed up around 10:30 at night wielding the cutest little chainsaw I’ve ever seen. I was able to convince them that I needed to keep the woody debris for a restoration project, so they obliged and cut it into perfect lengths to fit the car.
Of course, then we had to deal with the City for damages. Since the city owned the tree, they were libel for property damages. At the time, it was typical for the insurance firm contracted by the City to push back and deny claims. Of course with those kinds of odds, we were initially denied. They tried to tie the “book value” of our old, yet well-maintained vehicle to the claim. I firmly told them that just as my house is property, my car sitting on the driveway is property and besides, they were not my auto insurance company.
We caught a break. At the same time, the Toronto Ombudsman was investigating the issue of the high rate of denials, to the tune of about 94%. So, between the increased scrutiny of the insurance claims issue and our persistence to the point of being ready to take the City to small claims court, they settled for the exact amount it cost to fix the car.
It’s an old cliché, but you can fight City Hall. More importantly, sometimes you can win.
In 2007, Toronto put together a plan to double the tree canopy from about 20% to 40% by 2050. In the report, Every Tree Counts from the City of Toronto, Parks, Forestry and Recreation Department they identified the most effective strategy for increasing average tree size and tree canopy is to preserve and manage existing trees in the City. So throw out the idea of replacing mature trees with a bunch of “saplings”.
Some of their findings:
We have just over 10 million trees in Toronto; 40% of which are on city property with only 6% as street trees.
The average tree diameter in Toronto is 16.3 cm (6.4”). Only 14% of Toronto’s trees are greater than 30.6 cm (12”) in diameter.
The size of a tree and the amount of healthy leaf area equates directly to the benefits provided to the community, e.g., a 75 cm tree in Toronto intercepts ten times more air pollution, can store up to 90 times more carbon and contributes up to 100 times more leaf area to the City’s tree canopy than a 15 cm tree.
The trees in Toronto store 1.1 million metric tonnes of carbon annually or the equivalent of annual carbon emissions from 733,000 automobiles, as well as reduce energy use from heating and cooling of residential buildings by 41,200 MWH ($9.7 million/year), improve air quality by intercepting 1430 metric tonnes of air pollutants ($16.1 million per year) and mitigate storm water runoff.
Toronto’s urban forest is estimated to be worth approximately $7 billion and provides over $60 million per year in ecological services.
The benefits derived from the urban forest significantly exceed the annual cost of management.
How does my tree fit into the scheme?
Being larger, it is in the minority. My Norway maple is about 80 years old with a dbh of about 68 inches (173 cm), but with a sparse canopy. Unfortunately, it has dropped small and large branches. However, it provides shade on the front of the house and still allows me to grow a variable, native garden beneath, which wouldn’t happen with a healthy Norway maple. Even with a reduced canopy, the maple is still of value to wildlife and the community. I admit it begrudgingly.
Street trees do die and for many of them, it’s a premature death given the harshness of the urban environment and their location of living on the edge (average of 8 years for newly planted trees on the boulevard.). At the rate we are losing trees, exasperated by paving over of green space, is our goal of 30-40% canopy cover achievable? Perhaps so, if we can convince private property owners to plant trees, since they represent the guardians of 60% of the canopy cover. Our main proponent is LEAF.
Toronto has a program for replacement trees abutting private property. The list of trees include those found in southern Ontario, North America (Carolinian forest types) and outside the continent. Norway maple was removed from the list quite awhile ago. Ashes, both native and European were removed recently due to the decimating effects of Emerald Ash Borer. The list of native species is very short: maples (sugar, black, red, and silver), oaks (black, red, bur, chinquapin, and swamp white), hackberry and ironwood. Ten species are native to North America and thirteen species are native to Europe or Asia or are hybrids, including a silver-red maple hybrid – Freeman maple (Acer x freemanii).
The trees are not chosen for the wildlife value, but only for their ability to withstand the urban environment, particularly on the boulevard. Hopefully, residents will choose native trees over exotics to boost wildlife value, particularly with the pollinators.
Yes, size matters to the City: the bigger, the better. A large-leafed tree with a big canopy is to be promoted. Note: smaller canopy wimps like serviceberry need not apply. Fleshy, fruit-bearing trees can be problematic, so they are skipped over. There was a concern about crabapple trees and wasps plaguing the boulevard…yet it is fine to have highly invasive mulberry trees (Morus alba) dropping purple rain all over the sidewalks?
I went ahead and bought the whole package: the house with Norway maple in tow. But I was always wishing the exotic maple was a native sugar maple or a basswood or an oak; a species with high wildlife value. And then I lived through the fall of acorn rain when a neighbour’s backyard red oak had a mast year and we were snowed in with a blanket of blooms; a copious flower crop and then acorns dropped in the form of little backyard bombs. Another line was added to the list of reasons to plant trees a good distance from a house’s foundation, besides giving the tree breathing space and to allay any worries of Jack & the Beanstalk imagery. Maybe it was all well and good that I didn’t have an oak in the front yard. But a basswood would have been nice.
According to Douglas Tallamy, basswood, as a single species, is host for over 150 species of caterpillars in North America. And using the Tallamy table in his book, Bringing Nature Home (pg. 147) on a per-species basis, this makes basswood the most productive of all the trees. It would be a beacon for neighbourhood butterflies and moths; the only one on the street, as far as I know. Heaven knows, I have to keep up with the neighbours who have an American beech tree, a sole species in the genus Fagus and host of over 126 lepidopterans.
My choice of basswood is not on the grand list for front yard planting, probably because it is salt intolerant. Instead Redmond linden (Tilia americana ‘Redmond’) is offered. Interesting that they don’t include the more commonly planted exotic ones we normally see: littleleaf linden (T. cordata) or the common linden (Tilia ×europaea), a natural hybrid of the small-leafed lime (T. cordata) and the large-leafed lime (T. platyphyllos) from the Netherlands. (More detail on Tilia).
However, if I go with the basswood, I may not escape flower or seed drop and especially aphid rain. But, it sure would make up for it in attracting lots of pollinators.
I would miss this view if the Norway maple was gone.
Norway maple – love it or leave it?
I could move or just live with it. But for now, I’ll live with it while I pick out its seedlings in the spring and watch out for gusting high winds.
Originally published June 26, 2013 on Native Plants and Wildlife Gardens