Re: Re: classifying as a Rebloomer
iris@hort.net
  • Subject: Re: Re: classifying as a Rebloomer
  • From: L* M* <1*@rewrite.hort.net>
  • Date: Sat, 04 Oct 2014 07:22:36 -0400
For my breeding program, my assumption has been that coastal/California sporadic elsewhere style rebloomers have a goodly dose of those secondary characteristics necessary for rebloom. I agree that assumption may or may not be correct, but it seems to be working for me.
In my climate (USDA zone 7, rapidly approaching 8, erratic rainfall, erratic freezes, high summer heat and humidity), disease resistance/tolerance is <much> more important in my breeding program than cold tolerance.
I'm guessing that in colder climates, disease tolerance may be less crucial than ability to survive frozen soil. So Chuck and my choices of what is suitable breeding material differ.
Another big difference is that I want irises that are capable of bud set in higher temperatures than Chuck needs in order to have rebloom start at least one month, preferably two, before they are killed by fall freezes. Average killing freeze here is mid Oct, so my goal is bud set 6 weeks <before> mid August, when I'd like bloom to start here. Hot, humid, and horrid here in July.
Because the climate in coastal/CA/OZ (i.e., iris heaven) doesn't require high tolerance for freezing <or> diseases that result from constantly wet foliage, breeders there have been able to develop all manner of patterns, colors, and rebloom traits in irises that don't thrive (or survive) in more stressful climates. While iris heaven does cool at night more than here, at least irises bred there have to tolerate high daytime temperatures.
I have bought (and killed) a <lot> of coastal/CA/OZ bred irises because I think the flowers are beautiful - I love both the form and the colors and patterns. Using pedigrees and with information from others in climates similar to mine who have also bought and killed irises bred in iris heaven, I have been able to add about 30 different 'bloodlines' from iris heaven to my breeding program, with seedlings from another 10 being evaluated. Only about 12 of these ~40 pollen donors have survived here more than a year or two. By crossing them onto very disease resistant rebloom parents, I have gotten very strong, healthy seedlings from ~30 of them.
Although I've not exclusively used cultivars known to rebloom in iris heaven, when shopping, I've tried to include that trait. At least 19 of the 40 have been reported to rebloom somewhere at least once.
I hope that helps clarify some of the differences in Chuck and my choices of cultivars suitable to include in our breeding programs. 

On 10/3/2014 8:52 PM, Chuck Chapman wrote:

What you need from the  other parent is good secondary characteristics.


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