Q.I Read The Reasons Why My Hydrangeas Are Not Blooming. Last 2 Years, I Only Trim Dead Branches. I Live Near Niagara Falls,ON. I
would like more flowers this year. the leaves are already comming out. there are 2 pics from March 20, and oct 2020 other july 2020
Certified GKH Gardening Expert
It looks like you get a few blooms. Make sure you aren't overfertilizing. Too much nitrogen will bring a lot of foliage but reduced blooms. In fact, most hydrangeas do well without any fertilizer. It looks like they may get a lot of shade. Hydrangeas do best with morning sun and moist soil. They may not be getting much rain under the eaves.
It is the bigleaf hydrangea, and you are right, it blooms on previous summer's bud development. You can see buds on the early stems so you do not want to prune till after it blooms. Your type just has one big show. Unless you have the variety that blooms on old and new wood, they won't rebloom the same summer.
So lack of blooms is not a pruning issue if you are not pruning, so here are some more ideas: