Well actually I do not rake the lava flow, just to make that clear.
Ok I was reading about rock gardening and I plagered the lines cause I was laughing so hard.
And my rock gardens are not Zen gardens alas - they are full of rocks however. I remember when we bought this place and had no idea that there were any gardens here. I started raking 3 years worth of pine needles aside and I said to my wife - It looks like vandals have thrown tons of rock into the flower beds. Why would someone do that? Then a Botanist friend came over and went nuts when she saw that it was a rock garden full of sort of rare rock plants, like the ones you see in bloom sometimes when backpacking along scree.
So my rock garden actually has dirt and plant roots between the rocks. The real plant is under the rock where its protected, and leaves and flowers pop out around the rock in the summer. One thing is that you need poor soil with sharp edged sand in it, or rather sand with a bit of dity in it.
Now my driveway is full of cinders and I DO rake that!!!