I would like to grow some small R. vireya in my unheated green house. Am I asking too much?
Mark
No problem as long as it does freeze in there. About 2c is about the lowest w/o trouble. Some of the alpine ones are said to take light frosts (i.e -1c with a temp bounce shortly thereafter) but they're so rare and beautiful I wouldn't risk a test.
Go fob the dwarf ones like St. Valentine et al as the others can get awfully rangy even with pruning. At one time I had about 25 or 30 of them until I couldn't no longer move in the ghouse. I gave them all away except for St. V, its sister, 2 saxifagoides hybrids (v v dwarf) and christinae x jasminiflorum (intermediate).
Extremely open mix with coir chunks and pumice in clay pots, underpot and never but never water when moist.