Here is a list of introduced irises that have bloomed for me during the
summer or early fall in KY over a period of 20+ years. Based on recent
records and earlier memories.
This group blooms quite a bit when established and even a little happy:
Feed Back, Sugar Blues, Total Recall, Pink Attraction, All Revved Up,
Cantina, and Immortality. (Star Gate has summer bloomed in a
couple of climates and may eventually join this group.) Feed Back is the only
one that kicked in this summer and I suspect it received water along with the
Newer irises (for me) that have shown this capability at least once (need
more testing): Again & Again, Lunar Whitewash, Lord of Rings, Luminosity,
Renown & Echo Location.
Some, like Violet Miracle, October Sky, Renown, Vanishing Act, Returning
Chameleon, Blazing Sunrise, & Champaign Elegance, Fiere Andre, have
bloomed in July or August, at least once. (Without
irrigation.) Returning Chameleon usually gives good fall bloom, but
not always as early as July.
Irises that are Repeat bloomers in my garden: Pure As Gold, Summer
Radiance, & Diamond Blush. These irises bloom about six weeks after
their spring bloom season. They can fall bloom in other conditions but
have not for me. Perfect Interlude gave repeat stalks for me back in the
late 80's and will occasionally show up on my lists.
There are many fall blooming cultivars, including Matrix & Violet
Miracle. I won't attempt to report all of these as they represent the bulk
of the rebloom cultivars. (my opinion)
I grow many irises, introduced in the past 20 years, which have been
reported to bloom off season somewhere. In a good year, many of these
start blooming late September and continue through a killing
freeze. Many have never bloomed off season for me.
Why do I list all of these, yet again? Just sharing the wealth!
These irises have the capability to bloom early in more difficult
climates and may pass it along to their children. It is my belief
that a heavy dose of these irises will increase the over all occurrence of
early, off season bloom.
Testing is on going.