I don't hybridize and I don't have a lot of seedlings. But I believe I am right in saying a lot of the large hybridizers plant all their seeds outside in the weather and let them grow. That way they get some idea of which ones are hardy and suitable for their climate. I know my little seedlings have been though freezes and frosts and now are getting pretty large. We are warmer down here, but I think even up north some of the breeders plant outdoors.
