Cultivar-specific hardiness?

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Does anyone have a list of cultivar-specific hardiness (cold/heat/sun tolerance)? For example, I have anecdotally heard that Japanese Maple Arakawa are very sun-tolerant. On the other hand, Japanese Maple Katsura are cold-tolerant (some people have apparently had success growing them in the ground in Zone 4).

I've personally noticed my Japanese Maple Ao Kanzashi and Katsura respond decently to late-Spring colds here in Zone 4 Minnesota — so much so I might do an experiment to see if I can grow them in the ground. On the other hand, Koto Hime was not cold tolerant at all! Anyone else have this kind of anecdotal experience or collective experience?
 

Deep Sea Diver

Masterpiece
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I’m sure we do have lots of anecdotal information on the trees we have. Yet there is a noted, more comprehensive publication called , “Japanese Maples” by J.D. Vertrees and Peter Gregory that lists lots of this information for most all the cultivars listed there.

Cheers
DSD sends
 
Messages
119
Reaction score
82
Location
Minnesota/Bay Area (depending on time of year)
USDA Zone
4
I’m sure we do have lots of anecdotal information on the trees we have. Yet there is a noted, more comprehensive publication called , “Japanese Maples” by J.D. Vertrees and Peter Gregory that lists lots of this information for most all the cultivars listed there.

Cheers
DSD sends
Thanks, I'll take a look at that. For now, I'm working with some Zone 4-hardy JMs (specifically, Ice Dragon and Northwind). Maybe I can start my own cultivars by crossing and selecting for certain seedlings ;)!
 

Rivian

Chumono
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I dont know about you but I have way more issues with them leafing out in march/april and then get hit by frost which is to be expected until early may. As soon as the buds start swelling they become susceptible to frost. Almost all the buds on my deshojo blackened. I asked the french seller guy maillot and he had frost damage on 5000 maples this year.
But as long as theyre dormant its not a problem here in zone 6. If there was a selection that leafs out as late as trident maples, all would be well for me
 

Mikecheck123

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It feels like you're glossing over a lot of important nuance. First and foremost, a USDA zone means something kinda useful, but also weirdly specific. It's means the average minimum temperature over a long time period (typically 30 years).

And when a plant is listed in a USDA zone range, that applies to the plant in the ground.

Therefore, trees in containers are more vulnerable and thus actually in a different effective zone than trees in the ground. But at the same time they can also be more easily protected (e.g. by placing them in an unheated garage during cold spells, or all winter).

Secondly, a tree surviving last winter does not mean that it will survive this winter. The USDA zone is an average, and temperature extremes can fall far outside of that average range.

Zone 4 is by and large outside the range for Japanese maples. So I would really look into winter protection (e.g. garages) rather than ground growing.
 

rodeolthr

Shohin
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Years ago, on the GardenWeb forums, there was someone in Duluth that had a.p. Emperor 1 growing in the ground for several years.
And since you're already growing a couple of the Jack Frost collection of trees, don't forget acer pseudosieboldianum, which is one of the parents in that line.

Regarding crosses of your 2 cold hardy trees, I think that you're absolutely correct. JMs are already so genetically unstable that you never know what might turn up in a cross between those two trees. I would certainly plant any resulting crosses in the landscape to see what sort of winter hardiness and unique leaf shape they might have.
 
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