Dear Kathleen et. al.,
Here in central AZ, several Puya species are readily available in the nursery
trade, especially in Tucson which is colder than here by several degrees. P.
alpestris and P. berteroniana are sometimes interchangably labeled.
I grow P. mirabilis and P. berteroniana in the ground and they do well with all
temps and all regular water. The former has multiple inflorescences emerging
from a clump and they are visually unrewarding but provide favored perches
for the nesting hummingbirds. P. berteroniana has that amazing iridescent
turquoise and orange giant (a science term) inflorescence that I have only seen
at Boyce Thompson Arboretum where, in the years it flowers, the event is
publicized in all local newspapers. P. laxa froze here in 2007 when we had
severe 12-hour hard frosts for three consecutive nights with temps at 18F for
four hours during each of all three nights.
I would personally not opt for pot culture ever with these plants. As was
mentioned, the spines are just too vicious for me...easily as nasty as Dyckia
and Hechtia. And flowering of P. berteroniana in my landscape is still years
out.
Best,
Pamela
Pamela Slate
P.O. Box 5316
Carefree AZ 85377