If the leaf is really all dried up you might as well take it off--if there's any green left you could trim it back. What I do when I put something in water and don't pot it up before it makes babies (I try not to do that!) is to put it in the smallest glass/jar/container that will give the roots some room to spread out, and then sift vermiculite, or verm/perlite, into the glass up to where the roots join the new plant or plants. Then leave them in that container for a week or so until the roots get over the shock, at which time they can be potted into regular potting mix. Sometimes if you pot them up directly the stress is too much and they won't make it, but I have found this method works quite well. Did you throw out the main plant? Often when begonias get too much chill they go dormant but come back quite well if given warmer conditions. I leave many of my begonias out all year and they usually get some frost and lose some or all of their leaves, but come back just fine when the weather warms up.

Thanks so much for the help, I knew better than to put it in water, but we were just leaving for the weekend and no time. I do have lots of begonias and love them but let a draft hit that one. I did save the old plant and its sending up a shoot now,for that I am grateful. I hope you are nowhere near the hurricane mess and keep safe.

new to begonias...
i am hooked on them!
any advice would be appreciated...
indoors under lights...now what?
thanks
suzanne

Need help/info on propagating begonia leaf cuttings. Anne