You're doing a lot of bigeneric crosses, WL. It's not unusual for incompatible crosses to sometimes set seed but the seed won't germinate.

To do a more meaningful test, try dividing the same grex into 2 batches and starting some in each area.

Thanks, I'll try growing some luddemanniana Rubras in the hot garage and see if they work. I just had some germinate outside (3 of 12 where albinos). I don't anticipate any verifiable bigeneric seeds for a few more weeks so I can't do a split grex anytime soon. Next up should be some xPortea seeds, but they are looking to go 4 or even 5 months before having ripe seeds and they probably self too so who knows what I have. At least I did carefully mark my crosses.

Mostly I'm worried about my recently planted La Noche seeds. I'd be disappointed if they didn't germinate. My B. distachia seedlings are quite interesting since there are so many differences. Maybe that is the key. Put pollen from several genera onto the same stigma and you'll get viable results. Although I can't imagine why that would matter.

I checked all the plantings that I moved from the hot garage to the cool outdoors and they all look to have some seeds germinating. I'm especially happy that the La Noche x Neo crosses are looking good, after being planted 8 days ago, with most showing good fluffy roots but no leaves yet.