Pretty typical for my area. This late, here, those flower heads tend not to finish developing into actual flowers.

PS: There is also a very active Hydrangea Forum!

https://www.houzz.com/discussions/hydrangea-forum-dsbr0-bd~t_29934

My Endless Summer-series hydrangeas havent bloomed for years despite many attempts to move it, hold back on pruning, winter protect old wood, fertilize more heavily in Spring to kick start it. If you’ve tried some of my methods above and still no luck you’re not alone in zone 5. I did throw one in the compost pile and it had a few blooms under a pile of straw so go figure! Good luck but don’t invest too much time with it.

I did throw one in the compost pile and it had a few blooms under a pile of straw so go figure!

==>>> over the years.. i have had quite a bit of success with not only benign neglect.. but also active neglect.. in the garden i mean.. lol ...

as you said : GO FIGURE ...

lol

ken

for what it is worth, i have seen several species of plants out-of-sync this fall. prunus species are flowering as well as magnolia soulangeanas. we are just now starting to get cooler fall temps but this unseasonal flower production has been going on for about a month. this is not that uncommon and they will usually flower at their normal time next season.

Thanks for the replies. I looked at the flower buds the other day and they are brown and I don't think there's hope of any bloom. Will be curious to see what happens next season.