The leaves and branches are curling over. I see no other signs of distress: no purple veins, no yellow leaves, no fungus, no infestations (that I can see), and no limp and wilting leaves. The leaves feel thick and hardy, but they're curling over. I did notice a slight brownish tint to the underside of a couple of leaves on one branch (in the pics) but that's it. Any suggestions? I've checked the forums for some time with no luck describing this symptom... am I just worrying too much?

I live in San Diego and the average daily temp has been in the mid-70's. No rain, and no nightly lows below mid-50's.

I ask because the stuff can move on the breeze. Every year, my neighbors damage my plants with their weed killers.