Back in November I bought a Viola odorata 'White Czar' at Berkeley Hort. The plant really didn't look great. The blooms had faded and a couple of them had set seed. But I saw an opportunity to turn a $5 purchase into many plants.
Everything I've read says that germination of viola seeds can be erratic, but they mostly recommend a period of cold stratification. I've stratified other viola odorata seeds and had fairly good results, so I'm going with what I know works.
I collected the 'White Czar' seeds back in November and stored them on a cool shelf. Today I moistened some perlite in a ziploc bag, added just a splash of hydrogen peroxide to discourage fungus, and added the seeds. Then I sealed the bag, rolled it up, and stashed it in the fridge for at least the next six weeks. I've noted on my calendar when I need to check the bag and if it looks like they're starting to germinate at that time, I'll sow them in a seed starting mix and put them in the mini-greenhouse. If they aren't germinating, I'll keep them in the fridge and continue to check them.
One thing I forgot to do was count the seeds before I put them in the bag, but I think there were about 75 seeds. Even if I only get a 50% germination rate, I should get at least three dozen plants.