I tried growing begonias from seed for the first time this year. It was a complete failure. Most of them germinated, but not a single one made it to adulthood. A handful looked like they were going to do well, got to 4-5 leaves, and then died. Most died very young, a single leaf about 1/4-1/2" in size.

With a greenhouse you may do better than I. I just grow under fluorescent lights, in my studio which is on the cold side in the winter.

I think my biggest mistake was that I used the same fine peat based starting mix that I usually use for everything else. From what I have read a coarse mix is much better for them.

I have been very successful growing them from cuttings. What I should do is go buy a few plants right now, keep them in pots, and plan on cuttings over the winter.

There is a Begonia forum here, but it doesnt seem to active.

Here is a link that I found helpful.

Here is a link that might be useful: Brads Begonia world

I've grown Begonia semperflorens-cultorum several times. I've not found them to be a challenge, but I know that my "system " is different from others.

If you can find pelleted seeds, it will make the job much easier. Begonia seeds are eensy weensy. I also strongly recommend a two step method : 1) seed germination in a regular, bagged potting medium using bottom heat. 2) transplanting the tiny seedlings into individual containers for growing on.....no bottom heat and using a very porous medium. I use cell pack inserts and plastic flats. (18s and 32s)

Don't forget that begonias need light in order to germinate. That means you'll need to spray your seeds into the mix with a fogging nozzle or plant mister.

Do NOT use those awful peat pellets.

A regular potting mix such as Jiffy or Pro Mix is fine for germinating. Those super-fine germination medis are too fine

Keep the bottom heat on until all seeds are up, then unplug it. That's one very good reason to germinate the seeds in one flat. You can sow hundreds of seeds (depending on the variety) in one flat! That's pretty easy to heat. For my personal needs, I would use two or three seedling flats, which I would transplant into cell packs as soon as the seedlings can be handled. Two or three germination flats translate into several hundred plants, easily handled in their reusable plastic inserts and flats.

Once transplanted into the coarser mix, the plants grow like gangbusters. Be prepared to begin a fertilization routine.

Thanks folks! rhizo_1, would Fafards 3B be suitable for growing on media when transplanting to cell packs?

Also ..... If sowing a pelleted seed, can they be sown by hand?

This post was edited by cugal on Sun, Jul 21, 13 at 18:20

Yes and yes. I use an even 'barkier ' Fafard, but the 3B is excellent.

The pelleted seed can be individually handled with your fingers.

I germinated 4 different species of begonias this year. I was informed that humidity was the major problem and with growing them under either tall lids or ziplock bags opened daily I had no problems...crazy how they can be...ask me about rose cuttings....ug.

Thanks folks! Well, time will tell.......... I've ordered 500 pelleted, Ambassador Mix F1 seeds from Harris. There's some way cool Begonia seeds out there, but I thought I'd better stay with the cheapies until I figure these out........LOL

This post was edited by cugal on Mon, Jul 22, 13 at 22:21

Remember...there isn't anything unusual about begonia seed propagation....now that you've gone with pelleted seed. I can tell you how to sow a flat of the begonia 'dust' in case you ever decide to go that route. There are more varieties available in the unpelleted.

One hint that I think is important is to keep the soil warm through the germination period, but the surrounding air temperature needs to be cool. Heating cables or heat mats have been essential to the success of my seed germination and growing experiences over the years.

Good luck! I know that you'll do just fine. Your begonias will be lovely.

Thanks rhizo_1 for that vote of confidence! I'm set up with all (most) of the right tools to propagate, it's the knowledge & experience I lack, LOL .......

I am interested in learning to sow using the plant mister or a fogging nozzle (had to Google that one) that you'd mentioned earlier..........

I've grown begonias from seed. Several complete failures, some successes. I've got several containers of my homegrown tuberous begonias blooming right now. They're difficult because they're slow. It takes a long time before they get out of the tiny and fragile stage. If you've already grown other annuals from seed, you have the basic knowledge and experience already. And you have proper equipment, which makes it easier. My whole setup was kluged. I used a shop light in my living room and a DIY heat mat made from holiday lights.

I started dragon wing begonias from seed this year. I got 100% germination and survival. They were blooming by the end of May. I used rhizo's method. I use her method for ALL seeds! It works!