B. Lucerna Pictures by marksbegonias

Purchased these from ebay, they were labeled as "Spotted Angel Wings" I had an observation from the expert Terry Tasker who very kindly informed me that this plant is B. Lucerna.

Have these bloomed for you, well, they probably have for you. :-) I have one almost three years old and just doesn't bloom. Any suggestions? I haven't been feeding it. Would that do the trick? I took a cutting to work and that one started blooming. :-)

I had this as a cutting and it didn't flower the first year, but did this year. This plant has now been given to a friend because it was growing too big really. Most of my plants are for showing, and the space in the greenhouses is for the show plants. This would have been too big for taking to the shows really, and was starting to take too much space that i wanted for the plants i could take to the show.
All my plants i have grown in a mix of multi-purpose compost and dried cow muck (3 parts compost to 1 part cow muck). The cow muck is best if its turned black, fresh cow muck will burn the roots. Some growers say that this method can introduce disease into the plants, but i haven't had a problem.
The dried cow muck will disolve as the season goes, i don't use any other feed at all. (Only a little with the double tuberous Begonias when the bud first shows colour. Phostrogen). Too much feed can cause stem rot in the double tuberous Begonias, and i grow the other Begonias in the same way.
If you've no cow muck, a little feed may help - but i would be careful not to overfeed (it may be an idea to feed a silightly weaker solution than recommended, see how it goes and increase if you feel it's needed).
If the cutting that was taken to work started blooming, was that given feed? What conditions were different than for your plant? Light, Water, Heat? If it was at work did it get less water if it was left a little while - Begonias don't like too much water (I have always been told overwatering will kill more olants than underwatering). You may just need to compare these, adjust your conditions and you may have it flowering.
Good luck.

The cutting is just in colder conditions. I tried that with this one last year and got nothing. And I agree, this thing is huge! I let it pretend its a tree. Thanks for the info Mark. Its really helpful. I'll try a little feed, maybe to just get it going. :-) Thank you