Global Warming and Our Hostas

10 years ago

I live rurally in the Ottawa Valley but far enough away from Ottawa that the well known "heat island" effect of the city is absent. For example, last night, the official low at the airport was -27.4C (winchill close to -40C) which is about -18F. I keep my own weather records and consistly run from 3 to 5C colder at night than the airport. Last night was no exception coming in around -31C. This is, incidently, far from the record low for the date of -34C set in 1981 or from the all time record low of -40C.

The USDA puts Ottawa in Zone 5 but most of the rest of the Valley in 4 though of course the USDA class does not take into account the frost free growing days, rainfall, sunshine heat units or other important climatic details. It seems to me that for this locale, most of the gains from "global warming" are related to the higher night time lows than an overall even gain in temps.

Here we are frost free on average from about May 20 through Sept 12 and this is highly variable. The result is that hostas start to send up their first pips in mid May unfurling by early June. They last for just 100 days befopre being wiped out by an early frost.

Hostas are said to be hardy to USDA Zone 3 so certainly the Zone 4 conditions experienced here should have no effect. Are there folks on the forum growing hostas in Zone 3 or even Zone 2 (Saskatoon SK or Cochrane ON) to verify the cold hardiness? Is the length of growing season a more important constraint?

My hostas seem to be well adapted to the conditions but what I would like to get at is ... do they grow more slowly, do they take longer to reach maturity, do they present colour and texture better or worse. In other words, what represents the optimum climate for hosta rearing?

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Comments (10)

Steve Massachusetts
10 years ago
It's pretty cold here in Mass today. Windchill of -20 this morning temps down to 1 degree F. But yesterday in Minnesota it was colder there than it was on Mars. In fact the Governor of Minnesota canceled schools statewide on Monday due to extreme cold. How cold does it have to get in MN in order for it to be extreme?

What does this all have to do with global warming? Nothing. Repeat after me: "Weather is not the same as Climate."

Steve
in ny zone5
10 years ago
Good statement, Steve.
Comparing weather, for many years we here in upstate NY did not have yet the usual week of -20 dgrs we had in the past. The coldest temperature this winter might be in one night next week with a forecast of -12 dgrs. It is good to have more than 1 ft of snow covering plants right now. Bernd
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beverlymnz4
10 years ago
"Cold" in Minnesota? Its a balmy 18 degrees today.

Monday the forecast is for highs somewhere between -13 and -19 degrees Fahrenheit. Yes, I said highs. Strong winds are expected with predicted windchills of -30 to -50 degrees Fahrenheit. However, these are just predictions. The last time a Governor called off school due to cold there was quite a difficult conversation between him and our Superintendent. It never did get all that cold. We will see.
ctopher_mi
10 years ago
Hostas will easily survive the cold of zone 2, but that's usually with a good snow cover too.
User
10 years ago
I cannot contribute much to this thread, but I'd like to keep it up close to the top so others not present so far may comment.

It's interesting to me that folks endure one winter with such temps and are not packed to go to Someplace HOT! We're not all that warm here this week. Somebody left the door open between here and Canada....:)

Here is a link that might be useful: King of Someplace Hot
Babka NorCal 9b
10 years ago
One reason for not leaving snow is where your paycheck is coming from. After that...we had a daughter who was raised n Phoenix, and was thrilled to move to the upper peninsula Michigan. She loved the cold, snowy weather. Different strokes for different folks, I guess.

I have experienced more than several below zero years back in the mid west, and our recent mid-thirties nights here in Silicon Valley are enough for me...and wonderful for my hostas.

-Babka
don_in_colorado
10 years ago
Weather is not the same as climate. And don't call me surely.

Don B.
beverlymnz4
10 years ago
Last year we had a tough winter and the Japanese Beetles where less than half what they were the year before. This winter should wipe them out :) That's one reason to enjoy cold weather.

I did leave some hosta out in pots that won't make it. We'll see. I'm not giving up on the idea but I am trying some different methods...

Cold but not discouraged
Beverly
zkathy z7a NC
10 years ago
To get back to Dougald's question about what is the optimum climate for hostas, I've noticed that Tony Avent's PDN catalog (his zone is 7) lists hosta sizes about one size lower than most northern nurseries list them. I'm wondering if this is a marketing ploy or will my hostas never achieve the size of hostas that hibernate longer through colder winters? I've been siting hostas in beds dug for their mature size as I'm not getting younger while these babies grow up and moving big hostas in five years isn't on my list. Any observations from others familiar with growing conditions further south?
Kathy
zkathy z7a NC
10 years ago
Looks like my question has been answered in the corrugated leaves thread.
Kathy