You should mix peat moss with potting soil for succulents. Peat moss is good for succulents because it retains moisture while allowing oxygen into the roots. If you don’t want to buy peat moss, then you could substitute it with other types of mulch. For example, if you live near an apple tree farm, you might be able to find some fresh fallen apples instead of purchasing peat moss. Another option would be to purchase pine needles. They work great too.