I was going to say just the same. If they don't clearly announce that they are new wood bloomers, they aren't since it is a big selling point.

I know they are Kurt Weiss hydrangeas but understand they are from various breeders and some are overseas. They must have other names or German names but it seems such info is lacking on the internet.

In zone 7B, you might be able to test which type of shrub you have in the next year.... assuming Mother Nature cooperates and does not send a very harsh winter your way in Winter 2018-2019.

Old and new wood mopheads -normally- have a flush of blooms in Spring, unless winter is unusually harsh and kills all the stems. New wood mopheads then have another flush of blooms afterwards.

Until then and until you find some notes online, you may have to keep researching. I suggest searching the forum for these varieties' names and see if anyone who bought them already mentions whether they rebloom or not.

Timing of the flowering will depend heavily on location. In luis' very southerly location hydrangeas may well bloom in spring but further north, they won't start blooming until later into the summer. In my area - pretty far north - the only hydrangeas blooming before the end of June are those purchased already in bloom from nurseries or greenhouses!! And with a later overall boom, it is tricky to tell old wood flowers from those produced on new wood. There is no lapse between the two but rebloomers or those that flower on new wood as well will continue to produce flower buds (broccoli) late into the season, often continuing to bud and flower as late as October.

Two extremes of location - two very different bloom cycles :-) Most others wll fall somwhere in between these two.

It still should be easy to tell the blooms apart from new and old growth but not without some prep work.... I once put some green twine/tape around new stems of a Pistachio bush for other reasons. If you flag the new growth early on and check them for blooms later in the growing season, you can tell if new growth produced blooms. Just remember to remove the green twine or green tape when done.

Thank you all for your input. It seems like reblooming vs one-time blooming the former has huge advantages. Though I’m in zone 7B we sometimes do get extra cold winters and the Penny Mac I inherited did get killed to the ground level. I feel that I’m going backwards LOL getting these non reblooming Macs after I already planted a raised bed of 9 bloomstruck and Twist n Shout, Tuff Stuff as well as the very hardy sunloving panics (Little Lime, Firelight, Bobo etc) along the pathways. I could not help putting them in my cart when I saw their big healthy leaves in the store.

I guess it comes down to: Are the blooms of these 12 Macs so beautiful that they are worthwhile to be planted for their one-time blooms or no blooms? Or should I not waste my time? Any thoughts?

In zone 7b, I'd say you have a 75% of flowering on old wood without winter protection......or 3 out of every 4 years you should have flowers :-) You can bump that up to 100% if you winter protect.