A propos Hardy Plants -SA non bulbs
Angelo Porcelli (Wed, 14 Jul 2004 12:25:14 PDT)

Dear Jim

from my trials, which won't be of any use for you I guess, the hardiest
large-trunking aloes are marlothii and ferox, but they will die at -5°C.
Interesting is the natural hybrid A. x salmdyckiana (syn. A x principis)
between ferox and arborescens which coped much better of both parents in
several localities in Italy, during the infamous winter of '85, where
unusual lows were recorded in all south of Italy.
Aloe dichotoma, barberae, transkii all died as well the arborescent
Euphorbias (abyssinica, candelaris, this last name quite doubiously applied
to all these large euphorbias). Encephalartos from SA, the more common
(altensteinii, natalensis, horridus, lehmanii, ferox) all got damage to the
leaves but recovered. Carissa macrocarpa and Erythina caffra died too, and
many Strelitzia nicolai/augusta, while reginae recovered. So, this is rather
a list of non hardy SA plants for Indiana :-)

cheers
Angelo