While many across the GTA were scrambling to protect their precious plants yesterday, after Environment Canada issued a frost warning others — especially those in the downtown core — weren’t as concerned.
It seems that the risk of frost up until Victoria Day weekend, the traditional planting date, varies depending on where you live across the GTA, says David Phillips, senior climatologist with Environment Canada.
For example, Phillips says the odds of downtown Toronto actually getting a frost in May are pretty remote. However, in areas north of Highway 401 and the outer environs of the GTA, the odds are slightly higher. The reason for the microclimate in downtown Toronto is quite simple: It’s an urban heat island. The tall buildings, roads, cars and people radiate a lot of heat and keep the inner core much warmer than the suburbs, Phillips said.
To be safe, many gardeners — particularly in the outlying regions of Toronto — should wait until Victoria Day weekend to plant, said Duncan. “Traditionally it’s the May 24th weekend for our climatic zone … especially for anything tender and not frost-hardy,” he said.
According to Phillips the chance of a frost wiping out your outdoor plants in your garden or urns if you live in the city on or after May 11 is virtually zero.
