Are you planting the rootball too deep? Most of the shrubs you mentioned
actually benefit from being an inch or two above grade, especially if the
soil is clay. And, if the soil is clay, what about a drainage problem? Did
you tease the rootball apart before you planted the plants, or just plonk
them in holes? Potted shrubs can strangle from their own circling roots
unless you release them to grow out into the soil. How much are you
watering? Light frequent waterings or deep and infrequent? WHat have you
mulched them with? Fertilized them with? Did you have a soil test done to
know your soil composition, nutrition level, and pH?

There are so many factors to consider and you really haven't provided very
much information in the way of your planting and care practices.