Monday, April 13, 2015

Reblooming Irises in Zone 6:Cheerleading

by Betty Wilkerson

Here in my zone 6b garden, it is time to consider making new reblooming iris crosses.  Rebloomers are great for producing splashes of color in the summer and fall, but the breeding is best done in the spring, since summer can be too hot and fall pods often are frost damaged. Reblooming irises usually bloom during the first week of spring iris season.  Sometimes these early blooms will look fine, but will not produce any pods, since the early frost can wipe out the pollen. Be patient.  The pollen will return to normal in a few days.  In all crosses, including rebloom crosses, always use the healthiest and strongest irises available.

My friend in California has a full bed of irises that bloom all summer.  Why won't those irises rebloom for me here in zone 6?  It's both easier & harder than it might sound. The experts tell us they .don't have the genes needed to bloom in zone 6, most years.  Weather is definitely a factor, since some of these will rebloom occasionally, when the weather is mild.

I read through about ten of my old rebloom reports.  Keep in mind that there hasn't been a lot of work on rebloomers for our zones or area in the past twenty years. In the twelve years I've been at my current location, we've had a couple of mild summers, and here is a list of irises that summer bloomed for me during that time: 'Pure As Gold,' 'October Sky,' 'Lord of Rings,' 'Violet Miracle,' 'Feed Back,' 'Immortality,' 'Pink Attraction,' 'Again and Again,' 'Lunar Whitewash,' 'Over and Over,' 'All Revved Up,' 'Echo Location,' 'Returning Chameleon,' 'Cool Character,' ''Summer Honey 'and 'Summer Radiance.'  Most of these are fairly old when it comes to irises.  When we have a mild summer, with temperatures primarily in the high eighties and low nineties, we can expect a little bloom through out the summer.


'Pink Attraction'' (E. Hall 1988) photo from Schreiner's website.

'Pure As Gold' (Maryott 1993)

Due to their genes, all rebloomers are not equal.  'Pink Attraction' likes to be moved every two years, in order to rebloom well, and does not create rebloom children in my zone 6 garden. Two of my rebloomers that can bloom in the summer and also create a lot of reblooming children, are 'All Revved Up' and 'Star Gate.' When combined with other rebloomers, they do well.  Some feel that crossing the well formed irises that rebloom in California, and other temperate climates, does nothing to help us in the search for better form in the colder regions.


'All Revved Up' (Wilkerson 2006)
'Star Gate' (Wilkerson 2005)

'Echo Location'
is a very good rebloomer here and also produces reblooming children.  It might be a good iris to use toward breeding reds, since it has a lot of red blood lines from the Gibson side. These three, are all good for breeding reblooming plicatas.  Even though it doesn't looik plicata, 'Star Gate' has a lot of plicata blood and does breed some plicata.  'Star Gate' and 'Echo Location' are both examples of hidden plicatas.  Neither is a noticable plicata.  I hope to produce a good red on yellow plicata.with rebloom.

'Echo Location' (Wilkerson 2007)


There are three possible bloom seasons for rebloomers:spring, summer, and fall.  Some of us in the colder, roller coast zones have started working on summer rebloomers, giving us a better chance of seeing iris bloom during the years we have difficult spring and fall weather. Others don't want summer bloom for a variety of reasons. I'm not going to tell you how to create the best iris that both reblooms and meets all of the characteristics the American Iris Society requires for a spring bloomer. If I knew how to do this, I would have done it already!  I've come close but no brass ring!  

'Summer Honey' (Wilkerson 2013)
'Summer Honey' (Wilkerson 2013)
Crossing my plicata children onto my self children created 'Summer Honey.'  Several others from the cross, including some reddish seedlings , did rebloom.  I've been really impressed with the stalks still standing on 'Summer Honey' once the frost hit in mid october.

What cross would you make this spring in an attempt to promote rebloom in the colder zones?