Is your temperature measured or a guess? I have had problems with both species in the past and have found that a maintained temp about 24-25C (75-77C) to be crucial. I set my thermostat at 24C and have had much better luck. What variety of begonia are you trying? Imp's also have proved to be a challenge in the past and I set the mats at 23-24C, on memory (there is another post a few down about the same thing) I have found too hot with both species to have bad germination results. IMHE, being 21-23C to have better results than being to hot. As well both species have been cantankerous to germinate and I have had to wait 30 days in the past. Germination rates have been low (65%) for Imps, for me, in the past.

If you have extra seed (hopefully fresh) I wouldn't hesitate to sow more. They may not be full size to put out on your LFD but might be better than buying or nothing. Let us know how you make out.

Good luck

SCG

I am also having trouble germinating Dragon Wing begonias this year. I sowed pink (which were purchased this year) and also red (which were leftover from last year). I did get some germination on both after a good three weeks. The first batch was sowed on Jan. 16 in yogurt cups and on heat but I don't have a thermostat. I don't think I had this much trouble with them last year as I did have many beautiful plants. I probably sowed way more than what I ended up with though. After all this time I had hoped to have a better showing. I obtained more red seeds and sowed those yesterday. I'm not giving up on the first batches though. I would agree with the above poster and sow more seeds if you have them. I have to use a magnifying glass to see the sprouts in the first batch.

rubyshoes_gw Thanks for reminding me! During the germination and until the sprouts are of some size NEVER let the surface dry. Those tiny sprouts will disappear really fast when they dry out.

SCG

Thanks for your advice! Yes, SCG, all my seeds are on heat mats (with digital temp control) in a germination chamber. I have a temp variable of +/- 5F....... I use ProMix Bx in my seed starting flats with proper moisture, fresh seeds sown on top of media, with a good light source......

When I read here of folks germinating 241 of 250 of these same seeds on top of their fridge (without any supplemental heat, etc.) in paper cups, it makes me wonder what I could be doing wrong....... Am I trying too hard?......LOL

OBTW .......FWIW........ I've started over with fresh seed (even though it's a couple of weeks late).......... The only thing different this time is the temp..... I've lowered the digital thermostat from 75F to 70F (+/-5F)....... & I doubt this will make a difference....