Philip, all of the Kordes roses on your list that I’ve grown get at least some black spot for me, although I haven’t had them all for the same amount of time. They probably do better elsewhere, but in my garden, if a rose can possibly get black spot, it will.
–Earth Angel – still in a pot, growing vigorously but very unproductive of flowers (which have been small, although I’m sure that will improve with better conditions and plant age–their short lifespan might not); it was extremely healthy during the summer, but the foliage became progressively more spotted as fall wore on. The foliage didn’t drop quickly after becoming diseased, so the plant never looked bare and probably kept up relatively normal levels of photosynthesis. If the spots start earlier or increase in severity in the future, though, it might go downhill, but maybe it will improve instead. Overall, the plant seems almost like a relatively healthy Austin rose, and doesn’t resemble typical Kordes shrubs.
–Plum Perfect – I could swear that I have this one, but if it is the rose I’m thinking of, it’s not doing well and is not particularly vigorous, disease resistant, or floriferous. But don’t quote me on that. I’m hoping that the tag is out there, and will go digging for it when I have a chance. I sort of forgot/ignored it after its poor performance.
–Quicksilver – this hasn’t performed very well in my garden in terms of either black spot resistance or flowering.
–Dark Desire – I’ve had this for a number of years, and like yours it is a little less perfect in its disease resistance than it was for the first few years, but it’s still pretty good. It is excessively vigorous and extraordinarily (wickedly) thorny. The flowers are consistently good in color and form and are produced well through the heat for a Kordes shrub. Its fragrance has been very inconsistent, and was only strong for me one spring, which was a surprise; often it is impossible to detect more than a hint of scent, and I have a pretty sensitive nose. It sets some OP hips and I tried it once in a cross (with Oklahoma, just to see if its black spot resistance magic was heritable), but I only had a few seedlings and the black spot resistance was pretty much nonexistent. The flowers were single and about as close to black as anything I’ve seen, though. Maybe Dark Desire just needs a better partner.
–Soul Sister – this had poor black spot resistance and is gone now.
–Sunny Sky – the black spot resistance wasn’t great here, and the plant failed to thrive for me.
Of some other Kordes varieties that I’ve tried, Polar Express is doing relatively well for me. Laguna is looking decent for disease resistance so far, as is Kiss Me Kate, but they have some maturing to do before I can say much about flowering. Savannah Sunbelt has very nice flowers in spring, but the plant mostly shuts down in growth (entirely in flowering) during summer and the foliage gets very ratty. Tangerine Skies is somewhat healthy as far as I can tell, but so far blooms a little early in the season and then decides to take the rest of the year off. This summer (and fall?) shutdown seems to be a common theme for many Kordes varieties around here. I think that like many rose breeding firms, Kordes suffers from a failure to trial its roses adequately in diverse climates where its varieties are sold.
The hips that I got from Lemon Fizz with this year’s crosses weren’t overly large and didn’t have very many seeds per hip (probably 5-6), so I’m hoping for a good germination rate.
Stefan