This doesn't compare to Patty's gigantic piece of wood she showed off a while ago (I wonder if she got around to planting in it) , but I discovered this laying around outside the house and decided "here is this spring's future small planting project". Its a log I found along the beach years ago and I've used it as décor in my beds while living in several states and now I am thinking to plant into it. The planting space is approx. 8 in X 2 in and I call this a form of crevice planting. I am going to comb my noid semps and sedums and just choose the small stuff to plant into it.
Log with crevice(s)
Small type semps like the green with hair on the bottom right