Flower buds are located at the ends of the stems so the weird winter may have killed flower buds and resulted in less bloomage.

How much compost did you put? A 1/4" or 1/2" would be ok. I am concerned that larger amounts might start to cook the compost and affect the stems, causing them to flop from the bottom. Compost can be applied around the main crown from which all the stems originate. But do not add compost to the crown itself.

Can you post a picture too? I would expect some areas of the shrub, near the edges, to bend but not the stems in the middle.

Yes 2016 and '17 pictures if you can, please.

Thank you! Sadly, I don't have pics handy from last year... Here are some taken today! (Ps: definitely no more than 1/2" of compost, but it was definitely around the center of the plant ) . So I guess there are some stems standing up- the new growth! That surprises me because I thought the old growth would be stronger, but you can see that those are the ones laying down the most! Hmmmm....

I recall someone using rocks last year as mulch and also reporting that the stems were flopping.

Thanks guys. These bushes are about 6-7 times the size of that potted one!They're at least 7-8 years old! So I don't think we can directly compare. That said, they were very perky last year- still not as upright at the edges as a small potted one would be..

The rocks are the driveway- about 2 ft away from the crowns of the plants! They shouldn't be touching those at all... That's kinda the problem ;-)

There's no mulch around them of any sort and they're deeply watered.

They still wilt temporarily in direct, hot NC sun (a mechanism of some plants to conserve water even when well-watered, actually), but then bounce back as soon as they're shaded again. This spot gets a couple hours of full sun. But this pic is with them watered and not in direct sun. This is actually closer to the perkiest they've been this season. :-/

just my opinion but I would prefer smaller with upright stems than larger with floppy stems..try pruning?..hydrangeas are known to flop aren't they?..I clip my large Annabelles to keep them standing up..

Yes- me too! They die back completely in the winter and hubby pruned back the old wood, but since those are the floppiest stems, we'll prune them back harder next winter and cross our fingers!