Weather and Gardening Discussion

[Mountain Man]

The growing season is noticeably longer for sure, wonder if it means we will be able to grow more varieties of trees here. One factor that may work against that is stronger Chinooks in the winter, a week or two of warm temps can wake some trees up, then the next cold snap kills them .

 

[DougB]

Interesting. I have noticed the length of the growing season, nice to know it's not just my imagination. I've had a backyard garden for 24 straight years, and for the first dozen years there was a heavy September frost in probably 10 of the 12 years, and in the past 12 years it's been roughly the opposite. In the summer of 2022, the frost didn't hit the garden until mid October. Part of it is where the garden is located (near a retaining wall), and maybe there is some heat island effect.

Either way though, the growing season all around the city has been noticeably longer. A few other noticeable things. A couple of people in the neighborhood, have planted apple trees that are producing full sized apples, and some others have planted grape vines, and are getting grapes.

Biggest difference I've noticed is more moisture, be it more large rain and snow storms, higher humidity and greener grass

 

[Disraeli]

The growing season is noticeably longer for sure, wonder if it means we will be able to grow more varieties of trees here. One factor that may work against that is stronger Chinooks in the winter, a week or two of warm temps can wake some trees up, then the next cold snap kills them .

I think Chinooks are more a problem in early spring. I'm pretty sure dormancy is regulated by sunlight so they wouldn't wake up during December-february. But a week of 20 degree days above zero in late March followed by -10 days is havock

 

[Mountain Man]

I think ground temperatures are more of a factor in the spring, all the nutrients are stored in the roots, so when the roots wake up, the tree does too. Complete assumption on my part, but it makes sense to me lol.

 

[Ramsayite]

My most noticeable change is I have tomatoes that now self seed in a corner of my yard and are able to germinate, flower, and fruit within a season.

Something that used to only happen in, say, Ontario.


And yes, soil temp is the primary driver for plant emergence and growth rate.

 

[Surrealplaces]

My most noticeable change is I have tomatoes that now self seed in a corner of my yard and are able to germinate, flower, and fruit within a season.

Something that used to only happen in, say, Ontario.


And yes, soil temp is the primary driver for plant emergence and growth rate.

Same here lol. I've even had tomato plants grow from seed in the alley. The ones that have seeded in the garden have grown fruit, something that had never happened to me before until this past decade.

 

[Cowtown]

. Part of it is where the garden is located (near a retaining wall), and maybe there is some heat island effect.

There’s definitely some kind of heat island effect for Calgary. Innercity neighborhoods, always get flowers and greenery sooner than the neighborhoods on outskirts.
Is the heat island effect, affecting the air temperature or is it more affecting the soil? I don’t know, but it’s there.

 

[Cowtown]

Some interested food for thought, thanks to the now 5 year old Canada's Changing Climate report. Had some interesting statistics. Full report is here and is outdated, but still useful: https://publications.gc.ca/collections/collection_2019/eccc/En4-368-2019-eng.pdf

Relevant to this conversation is the 1948 - 2016 dataset comparisons (page 143)

Here's length of growing season. Note western Canada is lengthening the fastest, Calgary is somewhere between 15 and 20 days longer than the 1940s:
View attachment 601097

And the even more noticeable increase in "warm nights":
View attachment 601098

Again, this is only 1948 to 2016 data. 7 of the top 10 warmest years in history were recorded since 2016.

I don't have a clue if trees turning colour is a related to a warmth thing or more of a sunlight thing, but one of those two things is rapidly changing.

Another interesting thing to make note of, is those temperatures that they’ve been recording are on the fringes of the city by the airport.
I would bet that those numbers would be amplified even more for inner city areas.

 

[Mountain Man]

There’s definitely some kind of heat island effect for Calgary. Intercity neighborhoods, always get flowers and greenery sooner than the neighborhoods on outskirts.
Is the heat island effect, affecting the air temperature or is it more affecting the soil? I don’t know, but it’s there.

I would think it heats both. Sun shining on a wall will radiate heat outward towards plants and sun shining on the sidewalks and roads would warm up the ground beneath them.

I've been noticing the heat island effect over the last couple weeks, Point McKay / Parkdale is a couple weeks ahead of the trees in the Beltline in terms of colour or leaves dropping. Part of it may be the trees, my area is largely Green Ash and Poplar, the Beltline has more Elms.

 

[Surrealplaces]

I would think it heats both. Sun shining on a wall will radiate heat outward towards plants and sun shining on the sidewalks and roads would warm up the ground beneath them.

I've been noticing the heat island effect over the last couple weeks, Point McKay / Parkdale is a couple weeks ahead of the trees in the Beltline in terms of colour or leaves dropping. Part of it may be the trees, my area is largely Green Ash and Poplar, the Beltline has more Elms.

Me too. I was up in the outer parts of the northwest yesterday and the leaves on trees are further along than they are in the inner city.

 

[trtcttc]

Some pretty interesting maps in this paper for those interested, but we seem to have higher urban heat island effect in the core, particularly at night.

Variation in Urban Heat Island effect... | ERA

The escalating global climate change poses a more severe challenge, and Canada, as a high-latitude country, is experiencing heightened...

era.library.ualberta.ca

 

[JTron]

You beat me to it @trtcttc. 100% the climate down in the lower parts of the intercity are different than outer areas of the city.
My best guesstimation on the heat island effect for the core is a couple of things, one is the amount of concrete and cement, the other is elevation.
A few years back I used to do deliveries, and I had a temperature gauge in the vehicle showing the outside temperature, always without failure if I went from downtown up to say Edgemont, Hawkwood, Coach Hill or one of those neighbourhoods that sit at higher elevations the temperature would drop as I got higher in elevation, and the temperature would rise as I went back downtown again.
In the evenings during summer, spring and fall the temperature change was very consistent and almost always was about 5° difference between downtown and those higher elevation neighbourhoods. The difference was even higher around 9PM to midnight, where downtown and the Beltline could be as much as 10° warmer than Edgemont where I lived at the time. During the winter didn’t vary as much.
During summer fall and spring if I went from downtown out to a neighbourhood at the edge of the city in the south, such as Canyon meadows or Bonavista the temperature was usually about degrees 2-3 degrees cooler, and not as pronounced as it was for the northwest.
I've noticed 100% is downtown and Beltline retains its heat far longer after sunset than other neighbourhoods. This goes back to the amount of concrete and asphalt I would imagine.
Anyhow, this isn’t to say climate change isn’t having an effect, because I think it’s having an effect, but that the heat island is also very real.

 

[Disraeli]

I've definitely noticed more varieties of trees and plants around in recent years.

 

[Urban Outdoorsman]

I've definitely noticed more varieties of trees and plants around in recent years.

A big part of that are the new cultivars that are bred for the prairies. It's become increasingly common to see new types of zone 3 Maples, Honey Locust, Oaks and even Walnuts that can survive in Alberta. Granted many of these are on the edge, and some may see winter kill every few years but as we edge closer to becoming truly zone 4 that will become increasingly infrequent.

 

[Disraeli]

A big part of that are the new cultivars that are bred for the prairies. It's become increasingly common to see new types of zone 3 Maples, Honey Locust, Oaks and even Walnuts that can survive in Alberta. Granted many of these are on the edge, and some may see winter kill every few years but as we edge closer to becoming truly zone 4 that will become increasingly infrequent.

Most of those cultivars come from our east and are marketed as more prairie hardy varieties. Based on the US plant hardiness system, last year was the first sub zone 4 winter we have had in over 10 years. We've even had a few 5b winters. Our growing zone is comfortably a 4b at this point I would say.