My seedling grew over 4' last season in its second year. They are indeed fast growers :-)

How hardy do you think this tree is? It's native range would suggest z8, but, being a variant of A. saccharum, it may well be far hardier due to it's genetic background. It certainly could have retained cold hardiness from its ancestors...

At least zone 8, I don't think anyone really knows definitively.

Leafing out and growing already

Thanks for the pic. Looks vigorous!

I love these things!! Looking at the pic again gets me excited to watch mine grow this coming year. It is a tall skinny stick like the one you posted in the OP. Bark is green on mine and buds appear to slightly be swelling. As long as the buds made it out ok, I'd say this tree is solidly zone 7a hardy considering this past winter. Prolonged cold (not news to anyone) with two nights in the lower single digits.