Healthy plant but few flowerheads

[Marge]

I am in the North of England and have a three hydrangeas in the garden. They are all the same age (about 4 summers old), and are nice, healthy plants.

The problem is one of the hydrangeas has plenty of lush green growth but only a couple of 'mop heads' this year. I have treated all the plants the same way, in fact they are all in the same border.

What can I do to encourage more blooms on the lush one?

[luis_pr]

If this problem has not been resolved yet Marge, do you mind answering a few questions so I can put things into perspective? Can you describe last winter? Are the hydrangeas all the same variety (which variety?)? How, how much and when do you fertilize? How much sun does the problem hydrangea get? Has it suffered from soil moisture problems?