Got two plants from Erwin Geiger in fall 2014. When they had arrived, they were about 2 inches diameter each. Had been single plants that time. After Winter one divided into two heads, the other one has three heads now and they went smaller. Now they're about 1 inch diameter each head. One of them started to rot in spring, because it was very wet. I repotted both into pure crushed pumice. Maybe the reason for staying smaller. But now they are very healthy again. I always use pumice gravel for plants which look like having rotted roots. In my opinion the best way to heal them.
By the way here you can see a result: Semp. (tectorum) 'Triste' after having been repotted in pumice gravel, because they had rotted roots. The left one some weeks earlier repotted. Originally both plants appeared with the same size.
