I'm wondering what, if anything, I did wrong with my Endless Summer hydrangea this year. I'm in Central NH - the edge of zones 4b and 5a. I bought the hydrangea and planted it last year - maybe mid-summer. When I brought it home, it was partially in bloom, with kind of pinkish-purple-ish flowers. Much to my delight, the blooms turned the perfect blue color with no soil additives, and continued to bloom. Since it was the first year, I was uncomfortable with deadheading the spent blooms, so I just left them on. Around early September, a whole new round of gorgeous blue flowers bloomed all over the plant, providing vivid color when everything else had faded.

Last winter, I followed advice I'd seen online to cover the whole plant with mulch, to protect it. That was good advice - we got just about no snow until January. Of course then we got monster snowstorms every couple days after that... but in any case, I think if I had not protected it it would have died in the cold months before we had no snow. I uncovered it this spring, and it had died almost to the ground, but fresh buds were already growing all over it inside the mulch, and it quickly regained a full, lush look. It bloomed beautifully, all over, in early-late July.

Those blooms last FOREVER - but I didn't see any sign of any new flower buds, so I, perhaps stupidly, removed every single old bloom thinking it would encourage reblooming. I cut just under the flower - there were tiny pairs of leaves under each flower and I left those. I didn't want to risk cutting off any parts where the new blooms were developing.

Now, it's September 10. The only evidence of reblooming I see is ONE flower which hasn't opened yet. And, it's on a "branch" which did not flower in the last round. (I know because it was a bare spot... there wasn't even a full "branch" there during the first round.) I do see plenty leaf/branch buds along the branches. Is it just slow-going? Considering where we are located, I can't imagine there will be time for blooms to develop before the first frost. Should I not have deadheaded? Did I cut at the wrong spot? Also - I know they often force early blooming for a good show at the garden center - might what's going on this year be more in line with its usual bloom schedule (such that I will probably not normally get a second round of blooming before frost?)

Any advice is appreciated!