Five or six years ago neighbor gave us a healthy hydrangea saying it wouldn't bloom for her. In that time we moved it around to give it the best sun, etc. It bloomed one year...that's it. What's wrong?
Hydrangea Doesn’t Bloom
Certified GKH Gardening Expert
You may be lacking phosphorus. If there is a lack of phosphorus in the soil, plants will have little to no blooms. You can either use a phosphorus rich fertilizer or add some bone meal to the soil. These articles may help as well: https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-not-blooming.htm