I read the info provided on your site. Thanks, I have a hydrangea (don't now which type) coming up 4 years now and has not produced a single flower. I know it was suppose to be white flowers, but discarded the tag from it. It produces huge leaves and grows and grows, but not a flower to be seen. The leaves are growing on the old wood. I'm getting very frustrated with it and giving this year a last shot and then dumping it. I also have another hydrangea that was a beautiful when in the pot, but since I planted in the garden it hasn't flowered as well. It grows from ground up. On a good note, I do have one that produces nice blue mopheads.
Hydrangea Not Blooming
Certified GKH Gardening Expert
Before you trash it, the soil around the non-blooming hydrangea may be lacking in phosphorus. That can affect the ability of the plant to bloom. Adding some bone meal in the soil should help alleviate the problem in the future. These article will help you learn more (if you haven't already read them):