Hello Judy,
" ...so my goal is to bring them in at night when we get frost warnings then move them back into the sun during day. This way I can have blooms through winter. "
That sounds like it could work. It is possible that your zinnias might get Powdery Mildew, depending whether your miniature zinnias are Zinnia elegans (violacea) or Z. marylandica (Profusions, Pinwheels, or Zaharas). The Marylandicas are essentially immune to Powdery Mildew, while the Zinnia elegans are susceptible.
I work with Z. elegans (violacea) exclusively, so all of my zinnias are susceptible to Powdery Mildew. I protect my breeder-quality zinnias from Powdery Mildew by spraying them with a systemic fungicide, and that works quite well. I grow zinnias indoors during the Winter (we are almost certain to get a killing frost here in east central Kansas sometime this month) and I watch my indoor zinnias for signs of Powdery Mildew, like in this photo.
This is another photo of a beginning Powdery Mildew infection.
When I see signs of Powdery Mildew, I spray the infected areas immediately (I take them out into the garage to do the spraying) with a product containing the systemic fungicide Tebuconazole. Then I start including some Tebuconazole in their plant water to keep them immune.
Incidentally, unlike other zinnia foliage diseases which are encouraged by wet foliage, Powdery Mildew prefers cool, dry conditions, so wetting zinnia foliage does not promote PM, but may in fact be a control measure for PM on zinnias in a greenhouse environment. However, the basement utility room I grow my indoor zinnias in remains dry, and in really cold weather it becomes cool because the utility room itself does not have vents from the central air heating/cooling system. So I have to prevent Powdery Mildew on my indoor zinnias and use a systemic fungicide. You may or may not need to deal with Powder Mildew on your little zinnias.
As an amateur zinnia breeder I like to produce "exotic" zinnias, and this is a photo of one of my current outdoor exotic zinnia blooms.
Each petal resembles a tiny flower, and that is an effect that I want to improve on in the future. I also have several other zinnia types that I am working on. I welcome your comments, photos, and any questions you might have about your zinnias or any of this.
ZM
