Renegade maples, unpopular poplars and other troublesome trees

This was posted more than 12 months ago. The information may be outdated.

By CBC News Ottawa, February 17, 2020

Ottawa has a vibrant urban canopy, but sometimes our trees don't act the way we expect them to.

"Trees aren't just pretty objects that we put up," said Joanna Dean, an environmental historian at Carleton University, ahead of a talk last week.

(...)The renegade maple

Dean told Ottawa Morning about three trees that have caused trouble, the first being the Manitoba maple.

(...)They would spring up all over the place, Dean said, and one of the locations they flourished was Parliament Hill. A study in the 1980s revealed that the Manitoba maple was crowding out all the other trees on the slopes behind Parliament.

"These were weed trees ... these were runaways, they were escapees," she said.

Though the tree is no longer banned, Dean said, it's certainly not one the city encourages planting.

(...)Centennial crabapples

Another tree that's been discouraged in the city is the ornamental crabapple tree.

It was popular in the 1960s, said Dean, when Canada's Centennial Commission wanted the bright pink trees everywhere.

The city even gave 1,800 free trees to residents to plant on their property, and the National Capital Commission planted them alongside roads.

"But they turned out to be a problematic tree," Dean said. "In the fall, we have nothing but crabapples underfoot — and [that brings] wasps."

(...)An unpopular poplar

A third tree that caused tensions in the city is the Lombardy poplar.

It was brought over from Italy, and given its thick canopy, it was used to line Central Park in the Glebe.

"They made a lovely cloistered park," Dean said. "You couldn't see any of the houses. It felt like you were out of the city."

But if you lived next to the park, the trees also hid your entire view.

(...)A 'vibrant urban forest'

Looking at the history of Ottawa's troublesome trees has implications, Dean said, for how we currently think about our urban canopy.

She said it's important that we learn to live alongside trees, and also understand legitimate concerns that people have about some of them.

A lot of trees get removed, she said, because they're in someone's way.

"Until we realize how to work better with trees," Dean said, "we're not going to be very successful in creating a strong and vibrant urban forest."

https://www.cbc.ca/news/canada/ottawa/trees-ottawa-historical-urban-canopy-1.5462803