Q.Mophead hydrangea
My hydrangea bloomed 1 & 2 season with huge brilliant blue heads. Did not bloom again till 5 season. Few blooms small in size. Has not bloomed since. This was ninth season. We tried cutting way bac for winter and covered mulch. Tried leaving bush whole and covering with tarp. Have just left alone no covering. We are in zone 7. Bush is around 4 ft. High and 4 ft. Wide. Big healthy leaves. How can I get it to bloom again?!
Certified GKH Gardening Expert
This appears to be, either a fertilization issue, or a pH issue. It is always good practice to spread dolomitic lime each spring to keep the pH in check, but I believe that you would benefit from doing that now. You may also fertilize with an all-purpose fertilizer, but it is best to do that in spring. It could also come down to the fact that the type you have has a habit of dying back too far, as the flowers only occur on old wood. Here is a link to more information: https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-not-blooming.htm