Hydrangea question...?

I have beautiful Endless Bloom Hydrangeas. They are full and produce bright beautiful blooms. However, they do not grow up or out... just more full. Is this normal? I would like the plants to grow larger. What can I do to facilitate their growth?

Hydrangea question...?
This plant only grows to between 3-5 feet. If you have had it in the ground for a while, more than three months, give it some fertilizer. If you give it the type that is for acid loving plants it will turn a little bluer than pink. It is a beautiful plant. Keep it well watered, they love water, and make sure it has some shade at least in the afternoon.
Reply:If they get too tall the stems cannot hold up the huge blossoms, self defense by staying fat and not very tall. A rhododendron will get tall and covered with huge blossoms and has a woodier body. I had a lace cap hydrangea that got much larger and was awesome--also a pg gets big and tall and has huge white blossoms.
Reply:Hmmmmmm, it's almost sounds like the roots are all balled up. Do have a lot of clay in your soil, or rocks perhaps? Wait until the end of the bloom season before you go poking around the roots. This plant only gets to be about 5' x 4'. Good Luck