Her website says Boston. So I think zone 5b?

I am in zone 5b as well and several (but not all) can be grown here. There are some really nice varieties that will grow in zone 7, but not further north. The big issue to watch out for is deer. For some varieties like the pjm, deer won’t eat it and you can enjoy a nice large flowering shrub. For other varieties, the deer will devour the foliage on the lower four feet of the shrub. There are online sellers which indicate which zones each variety is hardy to and whether or not it is deer resistant.