Hi Nana,

You can grow it in water but it'd probably be better off in a fast draining mix. I have had cuttings in water for 2 to 3 months at times (in a terrarium or covered with a plastic bag) but they seem to do better in a soil-less mix. Just watch for water souring and algae growth (the algae doesn't seem to harm the roots but it can be unsightly).

I have heard of some experimenting with hydroponics but it doesn't seem to be a big trend with begonias. This is with a pump and a very weak fertilizer solution to keep the roots aerated and growing.

Let us know how it goes if you decide to give it a whirl.