Why Aren’t My Hydrangeas Blooming?

Question

I use 14-14-14 slow release fertilizer, however my hydrangeas don\’t bloom.I know they need phosphorus to bloom; is there too much nitrogen in the fertilizer? I don\’t prune the hydrangeas because I don\’t know what type they are. The smaller hydrangeas are 10 years old as is the larger one. They should have been blooming for several years! Any suggestions?

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Answer 1

These appear very low to the ground. This leads me to believe that they die back, fully, each year. If this is the case, then it may be that this cultivar blooms from shoots grown on previous year's wood. This will mean that the shrub is not suited for your zone, and can only be grown as a foliage shrub.

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

If you know for a fact that this is a cultivar that blooms on new wood, then you may want to check soil conditions. There could, definitely, be too much nitrogen in that case.

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm

As a last resort, you can contact your local extension service, and they may be able to help:

https://www.gardeningknowhow.com/extension-search