Hybridizers: It can be fun to breed your own zinnias - Part 4, 1 by Zen_Man

Zen_Man wrote:
Hi Caitlin,

I do grow zinnias indoors in pots, but not in a sunny window (I am in eastern Kansas, not Arizona). I use banks of bright fluorescent lights in our basement. Obviously I can't grow nearly as many zinnias inside as outside. I can grow a thousand or two zinnias outside, while I can grow only a few dozen zinnias inside. But they can be choice breeders, and they can add a generation or two to my yearly zinnia growing. And give me a pleasant brightly lit Winter hobby.

"I wonder if anyone has tried to breed hardier zinnias. Probably a lost cause!"

Probably. But it is not entirely beyond the realm of possibility, if you consider possible inter-species zinnia hybridization. The genus Zinnia consists of 19 species of annual herbs or perennial shrubs or subshrubs. Six of those species are shrubs or subshrubs, and they are all in Zinnia subgenus Diplothrix. The only species in Zinnia subgenus Diplothrix that is cultivated extensively as an ornamental is the Rocky Mountain Zinnia, Z. grandiflora.

The Rocky Mountain Zinnia is a perennial subshrub that is cold hardy to U.S. Zone 4 and it is also drought tolerant. So some zinnia species can be fairly cold hardy, but not the Zinnia violaceas (also known as Zinnia elegans) that I am working with. As far as I know, no one has tried crossing Zinnia elegans with the Rocky Mountain Zinnia. I think it might take some high tech bio-engineering to make that cross work. I'm not ready to tackle anything like that, just yet. And I am not sure that hardy zinnias would be a good thing, anyway. However, when I watched my "shrub zinnia" develop, I thought of those six species of wild shrub zinnias. Attached is another picture of my "shrub zinnia", taken before a killing frost got it. So it wasn't cold hardy.

ZM