For some reason, these were more vulnerable to freezing temps, when we had a sudden plunge. I lost seedlings of these but the Redman Super and the Burpee Rose Giant (both Zinnia elegans) weren't phased. So I resowed the Lilac Emperor and the next batch of seedlings was attractive to the little garden slugs here and comparatively few of them made it to a size to be planted out. So I direct sowed next to the seedlings, in order to have a good stand of these. Enough of them made it through!