The Tree That Smells Like a Dumpster Fire
Every autumn, a familiar stench descends on certain Toronto neighbourhoods — and no, it's not the compost bin you forgot to take out. It's the female ginkgo tree, and residents are done putting up with it.
The ginkgo's fruit, which ripens and drops in fall, produces a smell that arborists, city councillors, and long-suffering homeowners have described as somewhere between dog poop and vomit. It's a combination of butyric acid (the compound behind rancid butter) and other organic compounds that make the sidewalk beneath a female ginkgo genuinely unpleasant to walk past.
Healthy Tree, Horrible Smell
Here's the frustrating part for city officials: these trees aren't sick or dying. Ginkgos are actually remarkably resilient — they're one of the oldest tree species on Earth, having survived for over 200 million years, and they tolerate urban pollution, compacted soil, and harsh winters better than most species. That's exactly why cities across North America planted them so enthusiastically in previous decades.
But nobody thought hard enough about the smell.
The problem is specifically with female ginkgo trees. Male ginkgos produce pollen but no fruit, while females drop the notorious fleshy seeds each fall. When cities planted ginkgos decades ago, they often didn't distinguish between the two — or didn't have reliable ways to tell them apart until the trees matured and started fruiting.
Residents Push Back
Toronto homeowners have been contacting their city councillors asking for permission to remove the trees, even at their own expense. Under most municipal bylaws, street trees are city property, meaning residents can't just take a chainsaw to them — even when the tree is technically on the boulevard in front of their home.
City officials are caught in a tough spot. Urban forestry programs across Canada have been working hard to expand tree canopy coverage in cities to combat heat islands, improve air quality, and boost mental health outcomes. Removing healthy trees — even smelly ones — cuts against those goals.
Some municipalities have found a middle-ground solution: injecting female ginkgos with growth-inhibiting treatments that prevent them from producing fruit, essentially converting them into odour-free trees without removal. It's not cheap, but it keeps the canopy intact.
A Canadian Urban Forestry Puzzle
The ginkgo situation reflects a broader challenge for Canadian cities as they try to balance ambitious urban greening targets with the day-to-day livability concerns of residents. What looks great on a tree canopy coverage report can smell terrible in October.
Ottawa has its own share of ginkgos planted in older neighbourhoods, though the city has generally favoured native and low-maintenance species in recent planting programs. For any Ottawa residents who think their street tree smells off in fall, it might be worth a closer look at what species is actually out front.
As for Toronto's stinky sidewalks — the debate is likely to continue every autumn until cities develop clearer policies on female ginkgo management. In the meantime, maybe watch where you step.
Source: CBC News
