Thank you for your response!! I'm re-posting an email that sent I to your email just in case you didn't receive it. Yes, the one with the yellow blooms is not the cane variety but it is losing leaves as well. The one that dropped all the leaves this morning --more or less all of a sudden--was the spotted angel wing. I have three different begonias planted in a large container together all outside. I don't know what the third one is, but it's short and kind of clumped up, reddish leaves growing close to the soil surface--I think it's called a begonia :dewdrop." seems to be doing well. I probably put them all together in a too big pot I suppose and possibly overwatered after a recent short heat spell. Can you tell me why the container size matters? Is it because there is too much soil that stays moist for too long? Do you think I should repot the spotted angel wing in a smaller container with a faster draining soil? Maybe I can save it. Again, thanks so much for your reply.

Maybe you have red maple (Acer rubrum), with tar spot fungus.

The first plant looks like it has a watering problem. Either it got too dry while you were gone and the edges of the leaves were damaged, or it is getting overwatered and the roots are rotting. I see you have it on an automatic system. Did you ever find it badly wilted? If so, this is when the damage occurred and new growth should be normal. If not, then try taking it out of the pot and look at the roots. Healthy roots should be white and firm (older roots can become woody and darker, but should still be firm). There should be some new growth. Rotting roots will be mushy and discolored with little new growth. If they are rotting, take it off of the automatic system and hand water only when the soil gets dry.

Thank you all for those answers. I keep my citrus indoor but I've put them one or two week on my patio in the middle of summer. I don't know if it's sunburn because white spot continue to appears months after I've put my plants indoor and away from the sun. I think it's a chemical burn most likely. One time, and one time only (hopefully) I used a "water spray" for human face on my citrus to hydrate them. But the water contain sodium, sulfate, bicarbonate, chlorine, nitrate, silicon dioxide... :(