Don’t be afraid of using rocks. Bark is nice too, but it can discolor with time.

I spent 2 years digging rock out of a bed so it could be useful. Cypress mulch is one of the most advised by the pros for many reasons. A handy vehicle and length of chain will take out those bushes if the ground is saturated with water. Opt for a more open and airy installation of locally known plants that stand up to your conditions. Dwarf sized plant will stay in control better.