It was the morning before a hot September day and her freshness screamed for attention in the midst of a tired perennial bed. We were visiting the jewel in Kansas City known as Kauffman Gardens and here, standing before us, was the glorious yellow tall bearded iris, ‘Summer Olympics’. I wasn’t aware some irises have the genetic ability to rebloom and I had to learn more.
You may have seen national magazine ads offering reblooming bearded iris collections. But the ability to rebloom is very regional and some experts believe the key to success is selecting hybrids with proven performance in your USDA zone. The majority of iris hybridizing takes place in California (Zone 9), so most hybrid reblooming catalog claims are based solely on performance in that region. So I’ve contacted some local experts to find varieties that have been proven to rebloom in our Zone 6 area.
Jim Hedgecock with Comanche Acres Iris in Gower, MO sings the praises of the sparkling white, and aptly named ‘Immortality’. He says “I see continuous bloom from May through end of the season and it was the first hybrid introduced to the market as an ever-bloomer.” From my research, if you can make room for only one rebloomer, this pick in known to rebloom in most iris growing areas of the country.
Another selection from this grower of over 2,000 varieties on 15-acres is ‘Feed Back’. Hedgecock says “This hybrid sports 6-8 buds of ruffled, blue-violet flowers on strong well-branched stems. This midseason spring bloomer is noted for its sweet fragrance. ”
Butter yellow is an apt descriptor for the color of the beautiful and wonderfully fragrant ‘Harvest of Memories’. Hedgecock says “Both of these hybrids are very reliable rebloomers here at Comanche Acres in September and October.”
A two-time president of the Kansas City Iris Society, Jim Murrain has been growing irises since he was ten years old. He says “The hybrid ‘Earl of Essex’ is very different in color than most irises that can rebloom in Kansas City. It has a delicate tracery of orchid on the falls and a little heavier on the standards. You can expect rebloom in late September.”
From the same breeder as ‘Earl of Essex’, ‘Baby Blessed’ is a standard dwarf bearded iris only reaching a height of 10″. Murrain says “This selection is a fast grower and puts up a lot of flower stalks. It’s light yellow on the standards fading to white on the falls. This is a very reliable rebloomer in September and October”
‘Rosalie Figge‘ is a subtle interplay of violet and purple with a pretty, sweet fragrance. Murrain says “This variety is hailed as one of the very best rebloomers in our climate. It boasts a more modern form than most rebloomers and can bloom again any time in September or early October.”
Debbie Hughes with the Kansas City Iris Society has been volunteering at the Cohen Iris Garden at the Overland Park Arboretum since 2007. She said “The best rebloomer of the bunch out there is ‘Love Goes On’, which has rebloomed each year since 2010.” With pink standards and lavender falls, this bi-color is only available by mail order at winterberryiries.com.
Cultural tips from Tracy DiSabato-Aust in the gardening classic, The Well-Tended Perennial Garden: Planting and Pruning Techniques, include cutting all old stalks to the ground immediately after the first flowering. Deep, weekly watering during hot and dry weather is essential for success. Fresh new fans will appear and these are the sites of late summer and autumn flower production. Since twice as many fans are produced in a season, dividing frequently is recommended to encourage reliable rebloom.
In addition to regular watering through the summer months, Hedgecock recommends an extensive fertilizing regime of three applications of 5-10-10 in March, Late June and October for optimal reblooming.
Unless otherwise noted, all varieties are available at schreinersgardens.com. For more information, you can find The Reblooming Iris Society at rebloomingiris.com.