Supposed to be a 'rebloomer' so should flower on both new and old growth.

Thank you!

FI is a Mac, without winter protection you’ll be lucky to get blooms...SORRY https://www.pahls.com/plant-library/seaside-serenade-fire-island-hydrangea/

Why is that, if it blooms on new growth? (Obviously, I don’t know a lot about hydrangea.)

I’ve only had it through one winter and it has not made a single flower this year. My Endless Summer selections and Nantucket blue all bloomed well this year in MN.

We will see, I guess Thank you for the information.

Agreed. I live in zone 6 and Macros in my area won't bloom unless they are winter protected OR the winter was extremely mild with no late winter freezing temps or frosts.

same here. all macs are foliage plants in my z 6 Boston Suburbs garden. Getting rid of 3 of them soon.