You inspired me to start Sternbergia from seeds Poul after seeing that they can flower well even in a cold climate.
I only have few seedlings (nothing visible yet), last year they appeared in late fall and thus had a very short growing season. I was wondering what triggers them - cooler nights or the first early fall rains?
I am glad I have inspired you to grow Sternbergia, as I think they are a little overlooked maybe because they have a reputation of being shy-flowering. In general sicula and greuteriana flower very well for me in many different places and in both fertile compost and in almost pure sand without any feeding.
But they require some sun to flower well. Lutea do not flower as well as the other for me.
I think it mostly is temperature gradient which trigger the growt, but also humidity has influence.
Grown in a humid place the leaves appear before the flowers (as the one in my previous post). In dry places they often flower without leaves. But the flowering time is almost the same for the same clone.
The ones below are the same clone but placed in dryer soil.