well, since you live near a canyon, I would not reccomend growing such fruits, as they are better suited to the coast or the hilly regions. Longkongs/Langsats seem relatively hardy so far, star apples will suffer damage easily at 40 degrees and below. If I were in your situation I'd either a)move to a better location b)grow them in a greenhouse and c) grow the various delicious stone fruits available. I'd rate the langsat around the same as mahogany trees in terms of hardiness. It does seem to make a good houseplant