Hi Jai,
" Do you know what a cactus flowered zinnia combined with rolls/tubes would look like? Just curious. "
I don't know about extreme roll x cactus crosses, since I don't have any purified extreme rolls. I have made several cactus x tubular crosses, with several different type results. Some are just different looking tubular zinnias. Some strongly suggest the possibility of new petal forms, part tubular and part "open".
I am just beginning to see the results of those crosses and, as they say, I "expect the unexpected".
" My Z. haageana seeds are the Nth generation of Persian carpet that I bought from somebody in Kentucky. So I'm not sure if they're still Persian carpet or not. "
There are some new Zinnia haageana cultivars you might want to try. One is Jazzy Mix from Burpee:
http://www.burpee.com/flowers/...
Another is Aztec Sunset. It is one of the Mexican zinnia cultivars offered by Swallowtail.
https://www.swallowtailgardens...
Aztec Sunset and color selections from it are low growing zinnias, which might fit in with your indoor growing conditions.
" If I successfully raise them both (haageana and elegans) to bloom I may try crossing them just to see what happens. I imagine it's easier to use male haageeana parts to female elegans due to size, right? "
That cross has been successful in the past, so it is definitely worth a try. Just to be "on the safe side" I would try the cross both ways, and don't expect it to be a "pushover". The Z. haageana flower parts, both the pollen florets and the stigmas, are considerably smaller than Z. elegans. My few attempts failed.
ZM (not associated with any product or vendor mentioned or linked)
