How to ensure hydrangeas will bloom?

Hello M,

Me too, I have the exact same problem in zone 7.

I have reasearched this with the following finding —that might explain my situation.

In summer, branches produce new buds for the next spring. These buds stay dormant all winter and bloom in spring. If winter temperatures got too cold, or if there is a spring cold snap that kills the buds, non-reblooming Hydrangea macrophylla will not produce flowers that year.

There are hundreds of bigleaf hydrangea cultivars in

the trade, however, aside from flower type and color, the principal cultivar selection criteria is cold hardiness. Bigleaf hydrangea is rated as a zone 6 to 9 species; however, the shoot system (leaves, stems, and buds) of many cultivars are not hardy in zone 6 (areas west of Roanoke, Virginia), where average minimum temperatures for zone 6 are zero to minus10 F. In general, temperatures below zero F will kill flower buds as well as well as stems, but new stems may be regenerated from roots the following spring provided that the low winter temperatures did not kill the root system. Flower buds, but not necessarily stems, can be killed in the range of zero to 10 F.

http://blogs.lt.vt.edu/mastergardener/how-to-choose- a-big-leaf-hydrangea-for-your-garden/

Fertilizing will only give you more lush growth. Mine is in a Zone 3 and I mulched the base around it to stop the weeds and hold the moisture but that is all that is required. Check on line to see what is recommended for your problem.

Fertilizing is done throughout the growing season, not when approaching dormancy.

Here are some sites to help you out!

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-not-blooming.htm

https://www.waysidegardens.com/hydrangea-care-guide/a/324/

https://www.southernliving.com/garden/flowers/hydrangea-care