Now that I've seen others state on the Web that it has been a bad blackspot year for their roses, I feel confident enough to come out of the fungal-shame closet and agree that I've been entertaining the same thought. I don't know if it was the early March warmth or the cool nights of recent weeks, but blackspot has been a struggle at the K-State rose garden at this early date. In my own non-spray garden, I also believed that the roses were a little "fungus-ier" than normal.
So I resolved to note down the degree of blackspot damage on all my roses and did exactly that this morning. And, you know what? I think that maybe it is not quite as bad as I thought. I seem to have been misled by an early defoliation of one of my 'Prairie Harvest' (normally quite resistant), and the damage on my 2-year old Paul Barden rose, 'Jeri Jennings'. 'Jeri Jennings' definitely got the black spots aplenty, but 'Prairie Harvest' just seemed to turn yellow and defoliate all but the top leaves. I'm still not sure if that was blackspot-induced or drought-induced. She seems to be coming back. The rest of my roses are mostly doing quite well, in contrast to my undocumented impression, with exceptionally bad disease only on floribunda 'Rhapsody in Blue', English Rose 'Golden Celebration', and pink floribunda 'Gene Boerner'.
For reference's sake in this modern era of gigabyte data and online searchs, I will report the blackspot tendencies of three of my rose groups, the Griffith Buck roses, the Canadians, and the Old Garden roses, today and over the next two Mondays. Today, we'll tackle the Buck roses, at least those roses who are at or beyond their second season with me. The first number is the estimated percentage of leaves with blackspot and the second number the estimated percent defoliation. The list, of course, begins with Carefree Beauty, an Earth-Kind® decorated rose and often a resistant control rose in disease plot-tests.
Carefree Beauty 0%-0%
Country Dancer 0%-0%
Freckles 0%-0%
April Moon 0%-0%
Griff's Red 0%-0%
Wild Ginger 0%-5%
Hawkeye Belle 10%-20%
Prairie Harvest 0%-80% or 0%-0% (one defoliated, the other perfectly healthy)
Prairie Star 80%-20%
Winter Sunset <5%-0%
Earth Song <5%-0%
Quietness 20%-0%
Polonaise 0%-0%
Pearlie Mae 10%-0%
Golden Princess <5%-0%
Queen Bee 10%-10%
Honey Sweet 0%-0%
Folk Singer 0%-0%
Bright Melody 0%-0%
Iobelle 0%-0%
Golden Unicorn 0%-0%
El Catala <5%-0%
I noted roses with "<5%" above when I found a leaf or two with some blackspot, but generally the rest of the rose was unaffected. The health of most of these roses are not surprising, or should not be surprising for the Buck-bred roses, since Dr. Buck bred and raised his roses under a no-spray policy in a similar climate to mine. 'Prairie Star', 'Quietness', 'Pearlie Mae' and 'Queen Bee' seem to be the only ones that I grow currently with some degree of blackspot present. Other, that is, than the quandary that 'Prairie Harvest' is presenting me with. I have one bush almost defoliated and the other unaffected. I don't know if this year is a quirk from a rose that I've grown for at least 10 years and whose foliage is normally very blackspot-resistant, or whether the rose got damaged from something else like our current drought. Time alone will tell the me truth.
I don't suffer from blackspot but two years of winter kill on the roses has me crying in my beer. I mean wine. And, whining while I'm sipping it. Strange weather is seriously messing my gardens. :(
ReplyDeleteI’ll say. I watch your blogspot and I can’t believe, even at your altitude, that your flowers are that far behind ours. You need some Canadian roses for those temperatures.
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