Regular, but prior to flowering, use one with a higher middle number. How the plant behaves as a bonsai may be interesting if it's a perennial or annual, etc., plus whether the trunk part actually gets woody or not, and whether or not you could do much shaping - will it respond to bending or will branches snap?

Hi Lucy,
The trunk part is already getting a bit woody. The stems are kind of greenish brown but still soft. I know it has the potential to get woody because I searched one out as bonsai to see photos and was able to find several on yahoo. I included a link. It seems like it might be wirable. That's why I was hoping to find someone who'd worked with it. I six different books about bonsai and can't find it in any of them.

It is a perennial semi tuberous and forms this big caudex thing at the soil line. It supposedly can flower continuously from spring to fall so should I fertilize with the high P fert throughout these months or just keep it on an even system. I don't know if you can influence the energy it puts into growth or flowering, but I'd rather it put its energy into growth right now. I wonder if it would help then not to give it the higher P which helps with flowering. The phosphorus also helps with growth so it might be better either way. Thanks for the tips. Any other folks have a begonia that they've used for bonsai?

Here is a link that might be useful: {{gwi:9239}}

Oh wow! That's gorgeous. I don't know the plant at all- to me begonias are Rex and Angel Wing and that's about it, but I had no idea you could do that with one of them. I'd definitely give it a try if I had one.