Althea or Rose of Sharon is a flowering shrub that is very popular around here. It takes more water than the native plants do but less than a lot of other shrubs do - like the lilac. My mom had 4 very old and beautiful althea in her yard in Silver City, NM. They were there when she moved to the house on D St in 1970. We had no idea how old they might have been at that time but from the size of them it was considerable. They were still there when we sold the house after her death in 2007. As far as I know they are still there. They didn't take much water and were like small trees with their trunks being a good foot in diameter.
When I moved to Rio Rancho I took a handful of seed off of some of her althea and planted them in the first house we lived in and they grew and flourished and bloomed their beautiful purple-ish-pink blossoms. When I moved to the house I am in now I did the same thing by taking seed from the ones at the other house as they were two big to move. This photo is of the one I have now. Grown from seed in the past 11 and a half years.