Hmm...

So where I am, it has both Zones 5 and 6, so for convenience's sake call it zone 5, who with climate chicanery we might be nearing 4
https://palmsdirect.com/2017/11/usda-pl ... -zone-map/The lower the number the lower the average low temps
So if something rated cor as low as zone three, then I'm good
Lower numbers are better, I think, especially for bonsai, especially the smaller ones