I've been thinking about potting mix. I grow native plants just because. Kellogg's Cactus mix has the least nutrients of any soil I have found. Maybe Kellogg's with a lot of marble or limestone chips mixed in. "Calcareous soils in grassland, garigue and open places in pine woodland" doesn't sound like a wet place to me (my terrestrials all live in wet spots) so the cactus soil with added marble/limestone chips might work. I love experiments - I''m one of the few in the state of Nevada who has successfully grown Desert Peach (Prunus andersonii) but it took 5 or 6 years to be successful.
