I do not know the hardiness of this cultivar for northerner's .but in containers for northerner's and for anyone else this is a superior tree . Its pointy ruffled leaves are super cool. Coloration is phenomenal...and to top it off it is different not like any other cultivar I have seen. It's colors change constantly throughout the season and are highly dependent on where you put it but always gorgeous . Should be given afternoon shade as most JM do. For a smaller dwarf like tree of stunning looks that is unlike others this cultivar is a must have. The photos are from late summer in almost total shade so it is not colored up.
Winter Hardiness: Zone 5 - Down to -20°
Summer Hardiness: Tree will be planted in partial shade