Wow Sis, that is one large and awesome bowl.
You can paint it, stain it or just mix up some buttermilk and moss to paint it with. Place it in the shade and let it age. Meanwhile I would plant it with hardy type plants. Did you get one of those sweet species columbine? You could put that in with maybe one of the very tiny sedum (lydium, hispanicum) and one of the medium to smaller semps. Could even plant one of those awesome little species penstemon in it. Just think of the reward next year.
