Question
How do i make last years begonia cormes germinate

Answer
Brian,
I'm assuming that you just found them and that they're all dried up at this point, is that right? If so, you can pot them up in moist potting soil now and put them in a place that is bright but not in the direct, hot sun.  If they haven't gotten too dried up they will put out shoots. It is possible, however, that they have dried so much that they no longer are alive... only time will tell.

If you have already potted them up some time ago, and they aren't sprouting, be sure that they are in a warm location (but not direct sun) and that you water when the soil is going dry but don't keep them constantly wet. Begonia corms can rot if the soil is kept too wet.

If they are soft, in or out of the pot, they may have already rotted and there isn't anything to do at that point.

I hope this helps,
C.L.