I only wash old media off roots of plants when it's peat based. Were they covered when they were together and uncovered in their new homes? It takes seedlings a little while to adapt to drier conditions, and coupled with transplant shock I could see that causing them to fail. It might also be too co...

I usually get about 1/3 to 1/2 germination. They do fine sown in the GH in the spring without a plastic cover, just regularly watered. The same also works for Mahueniopsis (which has similar seed to Tephros). Chipping does not seem to affect germination. However, I have found that sanding down the s...