Back in July I saved a begonia from my trash. Not sure who put it in there, but I decided to take it out and see if I could do anything for it, and sure enough just watering it now and then did a world of good. It's been doing GREAT when it comes to growth, and has grown several times the size it started. However recently, several of the newer leaves have been getting thin, papery spots on them that tend to spread across the whole leaf. I'm not sure what's causing it and I'm hoping it's nothing too serious. Would hate for my new flowers to die less than a year after I got them. :( I've not watered it quite as much as I did when I first found it, as after repotting it I developed a slight gnat problem. I mixed a fair bit of used coffee grounds into the dirt and it was attracting the bugs. Could the problem be that I just need to water more? Or could the gnats be causing it? I don't seem to really have any around anymore, but it's hard to say for sure.
If needed I can take a picture in the morning of some of the leaves with the thin spots. I'd just assume it was a normal act of leaves falling off now and then, if not for the fact that there is at least one leaf on it that has been on since I found the plant. About half the leaf if all black and dried out from the previous owner's neglect, but the part that didn't dry out has held on very nicely.