What the spring 'Leaf Out' can tell us about how well the season is going

Nadine Powell
·2 min read
What the spring 'Leaf Out' can tell us about how well the season is going
What the spring 'Leaf Out' can tell us about how well the season is going

There are few better, and more welcome, signs of spring than seeing the first buds gently emerge, whether it's on the branches of trees, or ground-level early-bloomers like crocuses or tulips.

But they're not just pretty to look at. For scientists at the U.S. National Phenology Network (NPN) – 'phenology' being the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life – they're important markers used to track the progress of the season as it progresses.

Every spring, the NPN issues a 'Spring Leaf Out' and a 'Spring Bloom Out' report, which tracks the date at which lilacs and honeysuckle show their first leaf and bloom.

According to NPN, these are early spring shrubs and plants which are among the first of the season to leaf and bloom, and their Leaf Out report is based on recent temperature conditions for a region as a measure of early-season plant events.

Here's where things stood earlier this week:

NPN leafout Baron
NPN leafout Baron

While this data is primarily for the U.S., some extrapolation can be derived for bordering communities across southern Canada.

Interestingly, this year Spring Leaf Out is arriving up to weeks earlier across the northern U.S., and from the looks of it, across southern Ontario and Quebec too.

In High Park, Toronto, the ‘Sakura Watch’ is on, and the Cherry Blossoms are just about ready to bloom thanks to higher than normal temperatures over the last few weeks.

“In previous years, we’ve seen warm-weather trends mixed with mild winters contributing to early blossom blooms. 2021 is also shaping up to be another early bloom year for High Park.” according to Sakurainhighpark.com.

Peak bloom could run through April 28th, but how long they last will depend on the weather. The worst weather is heavy rain and wind, which can knock off the blooms prematurely.

Sakura in High Park 1 Steve Joniak
Sakura in High Park 1 Steve Joniak
Sakura in High Park 2 Steve Joniak
Sakura in High Park 2 Steve Joniak
Sakura in High Park 3 Steve Joniak
Sakura in High Park 3 Steve Joniak
Sakura in High Park 4 Steve Joniak
Sakura in High Park 4 Steve Joniak

All Sakura photos courtesy Steve Joniak/Sakura in High Park, used with permission.

Temperature-wise, at least, it's not hard to see why those Sakura blooms are emerging earlier in Toronto, and the city isn't the only part of Canada that's been blessed with a warmer than normal spring.

Looking at the last 60 days, temperatures were above normal from the central Prairies to Atlantic Canada, though cooler than normal across southern B.C.

Baron 60 day weather anomaly
Baron 60 day weather anomaly

Despite that slightly cooler trend in B.C., it seems this year’s Greater Victoria Flower Count was relatively typical.

B.C., because of the province's milder and less extreme temperatures, is usually the first in the country to see leaves and blooms. In any given year, the flower count in Victoria could be in the hundreds of millions, leaving the rest of us gripped with some mostly good-natured envy and longing.

And while there may be some areas of the country yet to experience spring weather, we know it’s only a matter of time.