Warm and humid with "bright shade" for lighting. We germinate in platic trays covered with saran wrap. Once the seedling get started we peel back the saran a little at a time to acclimate them to the harsher greenhouse environment. There is a very high mortality rate. About half will make it. Out of that lot there will be a handful that are vigorous, strong growers-the "keepers".
Interesting to see the Brugmansia sprouts. We have Brugmansia sanguinea sprouting right now.