plums just let germinate in a bag of peat moss in the shade

plums just let germinate in a bag of peat moss in the shade, pulling out the sprouty ones to pot up. I had an air prune bed planted oct 2022 and this spring (18 months later) keep finding new seedlings in it, I suspect the bed froze too hard to fully stratify them being above ground and not well insulated, so last winter I went with stratification in a fridge or root cellar and that gives the seeds a longer period above freezing. plum can need longer than most seeds maybe up to 5-6 months or even a warm period followed by cold, or even two cold cycles / winters. So in the bag until they germinate for this spring to monitor.