If using between pavers or stepping stones, it is recommended that you plant them such that the soil level is one to one-and-a-half inches below the top of the walking surface to allow room for the plants to compress when stepped on.Mulch is recommended to protect during winter in northern zones.Mazus likes good moisture but not wet feet. If you ever get areas where some of it starts dying off, make sure the areas dying off are not staying too wet or too dry. If the area has been too wet, spray a fungicide after the area dries out. Otherwise, if the area is too dry, water a bit more after removing any dead plants. If it is not obvious what is causing some to die, the best option is to have a sample tested.