Nothing major I hope? I have a kinda weird situation. Around the foundation of my house is a slab of concrete. It looks like a walk way that sourrounds the intire house. Not sure why this was done and what the purpose is? My plan is to take retaining wall bricks and build an area in which I had wanted to put shrubs, or flowers. The bricks are on the edge of the concrete slab and I would like to fill the space between the bricks and the foundation with soil. But I thought of one problem, no drainage. The wall is roughly 5 high, the height of the foundation. Can this be done without problems?? My concerns are drainage and root growth. Hope I explained my self.