My favorite cycad for here in the desert is the Dioon edule, var. palma sola. I have found them to be tough in cold and in heat, but you have to be sure that the variety that you are getting is the palma sola, not the ordinary edule.
The easiest way to be sure that it is a palma sola is to look at the new flush of leaves. New leaves on a palma sola are bright green (as you see in the picture), new leaves on a regular edule are brown. After the leaves mature, both plants are a nice bluish green. But I prefer the palma sola!
By the way, if your Dioon edule is flushing and the leaves are brown, that is perfectly normal, they will become green as the flush matures. If you thought that it was a palma sola, though, it is not.
