How do you take cuttings to grow a hydragea?

They are very difficult to root without specialist conditions. The easiest way is to layer them.You can take a branch of an azalea and lay it out on the ground and cover it with dirt. Then put something heavy on it like a brick.... Wait a year and go back and check and it will probably have rooted. Then you go behind where it is rooted and cut the branch and replant the branch in another place.... It will grow and be another azalea plant...