Nicholas Schwetz often walks the same route from his home at Charlton and Locke to the Good Life Fitness in Jackson Square. And after doing it for a while, he started to notice the state of the city trees along the sidewalk.

Some of them are non-native species. Some have metal grates hugging the tree trunks, sometimes so close that the trunks grow into the grates. Other grates are broken and people have stuffed litter into the tree pits.

It's spring, a time when buds open and leaves unfurl. But some of the trees on downtown streets aren't growing leaves at all.

Schwetz knows trees. He's an ecologist with a degree in environmental resource studies and a diploma in ecosystem restoration.

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Passersby have stuffed litter around the broken grate of one city tree at Main and Bay. (Samantha Craggs/CBC)

"As I walk downtown, I love seeing a nice lush urban area," he said. "It breaks up our landscape for sure. But why are we planting trees that are dead before they get to live?"

Schwetz took his concerns to Hamilton's public works committee at city hall on Monday. He presented photos and charts he made after taking inventory of the trees near Jackson Square.

He found trees that aren't native to the area, such as Scots pine and honey locust. He'd rather see native trees such as red oak or red maple.

Many of the grates around the trees are also too close and damaging the trees, he said. In addition to not growing leaves, some of them are growing shoots at the base, which stressed trees do in an effort to survive.

A Grated Community? Help us save some city trees choked by city grates. Send us a picture of a city tree that needs help, along with the location. We'll compile a list and make sure city hall knows about them. email cbc@hamilton.ca or tweet @cbchamilton

Schwetz suggests that the city remove the metal grates around most of the trees, give them more space to grow, and remove unhealthy trees and replace them with native species. He'd also like to see a better monitoring program. Otherwise, he said, we're planting trees just to see them die.

Trees strong enough for the city

Councillors voted Monday to ask staff to report back on the issues Schwetz raised.

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Tree trunk and grate merge at Bay and King streets. (Samantha Craggs/CBC)

Staff members choose tree species for heavy urban areas based on the appropriateness and resilience of the tree, said Mike McNamara, manager of the city's forestry and horticulture section.

Downtown trees have unique challenges, such as asphalt and heat from nearby buildings, McNamara said. And native tree species aren't always hearty enough to survive.

"We try to plant as many native species as we can, but it all depends on the environment there," he said.

The grates are placed around young trees so people don't step in the tree pits, he said. When a tree matures, city staff remove the grates.

Street trees by the thousands

If some are getting in the way of tree trunks, "we'll have to look at removing them," he said.

The city has about 140,000 street trees, which are trees located on any city road allowance. The city plants close to 6,000 new or replacement trees per year.

It is tough to find native trees hearty enough for downtown, Schwetz said. But with a little site preparation, red oak, serviceberries and red maples are options.

It's in everyone's best interest to pay attention to our street trees, he said.

"They improve air quality," he said. "There are a lot of psychological benefits of looking at trees as opposed to just concrete. If we're planting trees, we should make sure that they're healthy."