Notes about About Saguaros

This is not a Tucson specific site, but an excellent source for the life cycle of the Saguaro (Carnegiea gigantea).  I thought I knew a bit about them, but here is something new to me - Saguaros may only be able to propagate a few times a century!

"recent evidence suggests that Saguaro seeds germinate and survive in considerable numbers rather rarely, only after unusually propitious weather conditions facilitate this in particular   locales."  with ref to Dimmitt, Mark, "Cactaceae" in A Natural History of the Sonoran Desert, pp.84-93, Arizona-Sonora Desert Museum Press