In 2007, thanks to David Zlesak, I began working with the AgCan Kordesii breeding variety L83. My main interest in working with L83 was to improve Blackspot resistance in my work, but there was a likelihood that improvements in Winter hardiness might be had as well.
From the 2007 crosses I made, two groups stand out as having at least two or three selections that show both extremely good Blackspot resistance (near immunity) and apparent Winter hardiness (based on my limited experience). It should also be noted that several selections have good to excellent color and attractive bloom form. All have excellent vigor and attractive foliage. About 5 plants have been kept from the cross of ('Penny Ante' X 'Tradescant') X L83, including the fire engine red 77-07-23, which was used to a limited degree in 2009 breeding.
Illustrated here is the best yellow selection from 'Golden Angel' X L83, numbered 04-07-05. Some of you have probably noted that this is a cross of a triploid X a tetraploid, and so it is possible that the 04-07 selections are a mix of triploids and tetraploids. Some of these set open pollinated seeds last year (which I allowed to happen in order to determine fertility) and seeds were saved and a percentage have germinated. I am now starting to put select pollens on this yellow cultivar with the hope of moving forward with a Kordesii derived yellow breeding line. There is certainly a lot of room for improvements in both Winter hardiness and disease resistance in yellows! For now, I am limiting myself to using other first generation L83 hybrids to breed with this selection, and in fact will be crossing most of my best L83 selections with each other this year. Most are strong reds and medium yellows, so color results should be bright and rich with any luck.