Open this photo in gallery Volunteers plant acorn seeds in a tree nursery outside Eric Davies' rental property in Toronto on Sunday. Tijana Martin/The Globe and Mail

Tree planting is one of those quintessentially Canadian jobs that evokes visions of bug-ridden summers in lonely mountain valleys battling dehydration and madness.

But here it is in mid-October, on a day for woolly socks and pumpkin spice, and Eric Davies takes an occasional sip of craft beer as he and two volunteers sow around 1,500 acorns in the front yard of his Toronto apartment. It’s an activity so foreign in this leafy pocket of Little Italy that locals stop and stare. Some ask questions. Some continue walking in utter befuddlement.

In a four-metre-by-four-metre raised enclosure of soil and seeds, Mr. Davies, an ecologist, hopes to grow more than just a few hundred oak seedlings. His broader aim is to cultivate a social movement that will restore native tree species to their proper place atop the city’s botanical pecking order.

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“The value of local trees goes far beyond their beauty,” he says. “They are more resilient to climate change and very good for biodiversity. With a variable climate and insect outbreaks, we really need to be planting the strongest trees possible.”

For decades, that hasn’t been the case. Starting in the early 20th century, residents and city authorities favoured planting tree breeds from overseas. They were considered clean, pest-free trees that seemed to repel native insects and birds. “They were McTrees,” said Mr. Davies. “Nothing eats them because they’re so toxic. They grew fast, but we now realize they kill the soil, kill the diversity and create green deserts.”

Open this photo in gallery Eric Davies plants acorns in a tree nursery outside his rental property in Toronto as family members assist and curious passersby watch on Oct. 14, 2018. Tijana Martin/The Globe and Mail

Decades after being planted, the foreign trees continue to suppress biodiversity. In a recent study around the University of Toronto, Mr. Davies set up insect traps in four native trees and four non-native trees. The traps were checked every week with striking results. The ones from native trees would be crowded with moths, beetles and pollinators, while those from the invasive species yielded next to nothing.

Today, native species make up fewer than 40 per cent of the trees in Toronto. Of the top 12 street tree species in the city, seven are foreign, with only the native silver maple, red ash, sugar maple, and white birch cracking the list.

Their decline continues. Mr. Davies worked on another study looking at the forest health of Toronto’s ravines. In the 1970s, the invasive Norway Maple, originally planted as a street tree, comprised 10 per cent of the canopy cover in city ravines. By 2017, it had come to dominate the ravines, making up 40 per cent of canopy cover.

None of this will be reversed by a single a front yard nursery. But Mr. Davies hopes to prove that with a little local initiative, every neighbourhood could maintain a nursery or two. He collected over 10,000 acorns from prominent oaks all over the city, including a 200-year-old monster outside the Royal Ontario Museum, and donated several thousand to local schools building their own nurseries.

Open this photo in gallery The nursery is comprised of acorns from various native oak trees collected throughout the city. Tijana Martin/ The Globe and Mail Tijana Martin/The Globe and Mail

In the front yard of the Little Italy apartment complex where he lives, Mr. Davies and two neighbours nestle each acorn about four centimetres into a raised bed of triple-mix soil. Afterwards, they’ll stretch chicken wire over top to keep the squirrels away. And then they’ll wait. If all goes well, about 500 sprouts should emerge from the soil by spring. By the following spring, they’ll be roughly six inches tall and ready to give away to anyone who wants one.

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A high level of interest in the project from neighbours suggests there’ll be no shortage of takers. On a recent fall day, neighbour after neighbour stopped to look over the nursery.

“What on Earth are you making here?" asked one woman, stopping with her school-aged daughter.

Mr. Davies explained, followed shortly by a “Whoa, cool,” from the daughter.

“I saw it with my friend a few days ago and at first I thought it was going to be a hot tub,” the daughter added. “My friend thought it was going to be an ice rink.”

Mr. Davies says he’ll need volunteers to keep squirrels and weeds away. They seem obliging.

“Thank you for doing this,” said the mother. “It’s incredible.”