I've grown begonias for years but never from seeds. Sorry, but the only information I can offer is on propagation from leaf, stem, or wedge cuttings. Many hybrids revert back to original form when propagated by seed. I'd be very interested in any success stories. Cindy
i had 80+ species and cultivars before i moved to this single-digit-humidity state. I had species extinct in the wild. species with no name yet. a huge variety...ARGH
you can grow begonias from the extra-fine seed they produce, however you need to provide a warm, humid (but not overly damp) environment. one begoniac recommends using a covered shallow plastic container (something like a take-out tray) with light, moistened potting mix. wick the water out with a paper towl set below the container (which should have drainage holes punched). sprinkle the dust-like seeds on top of the mix and set some place warm. They are sensitive to damping off.
...but why do this when you can take cuttings!? unless you want to grow a species unavailable any other way, or make your own hybrids.
from watching my plants die, i would have to say the shrub-type begonias do best in arizona (inclusive of hybrids with other groupings). canes and some scandents do all right, but the rexes really suffer and many of the more exotic rhizomatous. you can look up more info on the american begonia society website, or peek in on the y! group. the y! group is for more advanced growers and hybridizers, but there are lots of little gems of knowledge there, as well as fabulous pictures if you get messages in your inbox.
here's a picture of B. pelata (used to be B. incisa) that is especially adapted for xeric climates. it actually does really well in the desert. It's a shrub type with peltate greyish-green velvety leaves on a woody stalk.
thanks a lot Ming, maybe I will re-think this out. sounds like more trouble than fun. I have been here 5 years and I know you only grow on the desert what the desert will let you grow. Ill think of something less of a heart breaker. Maybe bananas...LOL