As I’m sure many of you know, Monrovia is selling the first zone 4 Japanese maple that isn’t a cross with Acer pseudosieboldianum. It is Velvet Viking, Acer palmatum var. dissectum ‘Monfrick.’ These are grafted trees and I wonder what they use as rootstock in order to ensure survival in zone 4. I happened to pass by some at a garden center yesterday that have sprung growth from below the graft union and I took a couple photos. I wonder if anyone can tell me what it is - palmatum? Pseudosieboldianum? Something else? Grafting is not in my knowledge base so pardon me if any of this is unclear or erroneous!
Funny, 'Monfrick' is about equal to "mon fric" meaning "my cash" in French. :) It's reasonable to wonder why the rootstock is also good to zone 4. I've had times when the rootstock was more tender than the graft. The rootstock froze, the graft was fine. How many times will that happen here? -E
I appreciate everyone’s contributions, and I share Emery’s concerns. On the one hand, I do hear a lot of comments that JMs are less likely to freeze outright than they are to be damaged by wind, winter sun, or late frosts. So the confidence (hubris?) in using palmatum rootstock would support that notion. But I worry slightly about it jeopardizing an otherwise wonderful advancement, especially it is marketed as Zone 4, not just 4B, where the source tree originated (Minneapolis metro). I will certainly keep the forums updated in the coming years, as I have two in my yard, new this year.
I heard/read that the plain Acer palmatum species can withstand temperatures of at least -25°C when in the ground. They're probably more fragile when potted and need some winter protection where you live : a friend of mine spent 2 years in Minneapolis and from what he told me, winters can be pretty harsh there...
