I discovered that I had waterlogged clay soil, only grass grows and it gets waterlogged if it rains for a long time. I wanted to grow lilly pilly hedge so i decided to buy 2 metal raised beds, they are quite big. I filled the bottom half with wood chips and mulched leaves and the other half with garden soil from bunnings, will the lilly pilly cascades grow properly in the raised beds? I thought it was better than raised mounds as the soil won't wash away and they will be higher off the clay soil, the clay soil is soft not hard , and over time the raised bed will improve the soil underneath. Is this all true?