Hi Tina, I live within 10 miles of Augusta, Georgia, which I know is zone 8 and pretty much on the dividing line between 8a and 8b. Summer temperatures here are well into the 90's from June through most of September - - and sometimes start in May and don't stop until early-to-mid-October, plus we have high humidity. By the end of July our night time temperatures (I can hardly call them "low temperatures") are in the 70's. In a typical winter we might get one snow that actually sticks to the ground and maybe two or three times when the low actually gets into the 20's or upper teens for a day or two, but can then be up to the 60's a couple of days later - maybe even higher.
I have been slowly increasing the number of dormants that I grow over the last couple of years and will share what I have learned. I now have 15 dormant cultivars and many, many dormant seedlings including dormant X dormant crosses. Most of the plants grow and increase just fine here. I have noticed two that have up and down years. That is, they may grow well one year, then die back during the winter and come back the next spring with only one-third as many fans, but then increase and do fine through the next winter. Those two are Ruffled Strawberry Parfait (Reckamp, 2003) and Dragon Slayer (Polston, 2007). Heavenly Pink Fang (Gossard, 2004) has done this once over the five winters I have grown it. What I have had with some dormants, however, is rot problems particularly in years with a wet spring followed by a dry summer where I struggle to keep my garden moist (I use city water, often with restrictions on when and how much I can water). I lost Upon This Rock (Korth P-Korth L, 2004) and Alan Lane Agin (Agin, 2007) to rot plus several dormant seedlings. I also notice that some dormant seedlings (particularly but not exclusively those with Alan Lane Agin in the parentage) are susceptible to rot if I transplant them while it is still in the upper 80's or higher. Maybe these observations are because of something I am doing or not doing, so this is not to say that someone nearby couldn't grow them. Nevertheless, Cast Your Crown (Korth, 2008), Forestlake Ragamuffin(Harding, 1993), Mary Lena (Rice J, 2006), Ruckus (Rice JA, 2007), Susan Ruoff (Bachman, 2009), and a Korth seedling with Upon This Rock a couple of generations back in its parentage have never had an issue in my garden. Note: Both Upon This Rock and the Korth seedling had/have very bad sun-fading problems in my garden.) I do have a couple of "Southern" dormants (from Carpenter) that do fine too, and two that are registered dormants that do not go dormant, Shores of Time (Stamile, 2002) and Venus Flytrap (Gossard, 2007). I have a couple more that are in their first winter here.
Sorry I can't help you on the issue of deep purples that are not strongly affected by the sun. I bought several in this color group this past summer, but won't be able to tell you about performance until next year, and by the way, they are all planted where they get full shade from about 1PM through the afternoon.
Larry
