(longifolium x humboldtii). When I do a search, all I get is places to find them...that don't actually have them in stock. Help! I assume mini culture is close to pearcei?
Pretty much the same as P. pearcei, I would say that's correct. I never let these hybrids dry out, and keep them sitting in a shallow dish of water just like the bulk of my Phrags. There's a slight chance you end up with one of the "fussy" ones, which is what I call the Phrags that seem to appreciate drying out a bit. For those, I water them like Paphs more or less.
I currently have P. pearcei and P. Wössner Supergrande. I don't have P. Mini Grande specifically, but I do have quite a few very similar hybrids because I love miniature/compact long petaled Phrag hybrids and don't know when to stop!