Why this city plants 10,000 trees

Workers in the city's parks department planted their ten-thousandth tree this month, finishing a ten-year plan that started after a summer heatwave left some streets more than ten degrees hotter than others just a few blocks away.

The goal wasn't just more trees — it was more canopycanopythe overhead cover formed by the leaves and branches of trees, which blocks direct sun from reaching the pavement below. Streets with a full canopy can feel noticeably cooler on a hot afternoon than streets with none at all.

Planners mapped every block against satellite images to find the hottest streets with the fewest trees, and planted there first, mostly in neighbourhoods that had never had street trees before.

Not every young tree survives its first two summers, so the city trains volunteers to check for dry soil and loosen the stakes that hold each trunk steady as it grows.

The next goal is 10,000 more over the coming decade, with an emphasis on species that can handle hotter, drier summers than the ones the city planted in the past.