Here on the Oregon coast we can grow most cyclamen. I notice that most of them seemed timed to the rainy season here.. They can grow at the base of my spruces with equanimity. I have old plants of C. hederaefolium and coum and repandum. I don't know what happened to graecum but it could have been frozen out. It doesn't seem to matter whether they grow in the sun or shade although that might be a function of our cool weather summers. Here they come up in my grass paths. When I was in Italy at the beginning of October c. italicum was growing in the unmown grass in the Parco di Monstri in Bomarzo. That explained to me why they have such long stems on the leaves and flowers. The flowers were up by the grass seed heads. So they must like light. Whether they would grow in the sun without the protection of the grass 80 miles north of Rome is another question I can't answer. Can anyone grow coum where it's as cold as Indiana? Here the leaves come up in January and are pretty much gone by July. Larry