We have 8 hydrangea plants. I think they are called Ever Flowering or something like that. In past years, we have had wonderful displays throughout the summer. This year we have only one flower ! They are looking healthy apart from this.
Thank you for contacting Toronto Master Gardeners with your question.
Hydrangea macrophylla is best grown in rich, medium moisture, well-drained soils in part shade.
We recommend you to add early summer a slow-release fertilizer with a high percentage of phosphorus (the middle number in the NPK ratio). Phosphorus is the element that encourages roots growth and bloom production. You must stop the fertilization in by the end of July. Next spring you would add organic compost or manure to boost your plant.
Hydrangea macrophyla Ever® serie blooms on this year’s and last year’s wood. Prune these hydrangeas only if they are getting too large for the space or if you want to remove old flowers. The best time to prune them is after they flower in the late summer. If you prune them much beyond late summer, you will risk removing the flower buds that are developing on the current branches.