When we moved into our apartment in August of 2010, the Hydrangea in the backyard was in full bloom.

Hydrangea blooming when we moved in...

blooming in summer of 2010
That fall I researched how to prune hydrangeas and decided, based on photos and info found here, that our hydrangea must be H. arborescens, an Annabelle type. According to this very helpful site, these types of hydrangeas bloom on new wood (new stems), and that they usually “bloom every single year, no matter how they are treated. The only time they cannot be pruned is in the spring when they are preparing to bloom.” The site recommends that you prune this type of hydrangea back to a few inches above ground or to about 18″ – 24″ if you want to leave old wood to support the new branches and keep the plant from flattening in the rain.
So, that’s what I did. However, I also divided the hydrangea at the same time. It was enormous and was crowded in with a holly (which I have since dug up and given away as it didn’t have a mate and produced no berries.) I gave the hydrangea division to my friend Bev in PA.

Here is the hydrangea in March 2011, after being pruned and divided in November 2010

same day, top view
It continued to grow…

And here it is a month later, in May 2011: (note the cat hiding in my transplant tray!)
…and to become huge, green, and lush:

Hydrangea in June 2011
The only problem? No flowers! Not a single bloom all summer long. I am hoping that the lack of flowers was due to it having been divided the previous fall and not to an error in my pruning methods.
This year I have not yet pruned the hydrangea at all, partly because I’m scared to, and partly because the weather has been so strangely warm that I wondered if I ought to wait for colder temperatures…which are kind of upon us now. Is it too late?

Here it is now, not yet pruned...showing some buds on those stalks already.
Toward the end of fall I noticed powdery mildew on its leaves before they fell off, so I’m hoping that will not make a comeback this summer.
What do you think? Have I missed the boat on this one? Should I just let it be, or start chopping? (Oh, I know you YOU would answer this question, my good Linnie! You may be right!)