Living in Washington most of my life has made living with black spot more than common place. Each season I watch as the leaves turn from healthy shades of lime and evergreen to marred and sickly black. This spring before the buds have even developed black spot is all over my “Watercolors” rose. I don’t know what to do for this rose; I pruned it when I was supposed too, I have fed it, put mulch down, made sure I watered it down under the leaves, I’ve sprayed it multiple times and removed any effected leaves. This plant is in the a wiskey barrel on a porch, on a second story balcony under full sun. At this point I want to toss the plant out. The reason I chose this plant in the first place, is I purchased it from a reputable local seller and it is supposed to do well in this my zone. My other roses a not nearly as bad though they do have to be monitored.
Soooo after my disapointed rant I actually do have a question. Can anyone tell by the leaves if they are more likely to be black spot resistant? I noticed many of the roses that seem to do well are lighter green is there any connection?
I think there is a bit of a variance, some roses have more susceptibility to horizontal blackspot while others are more vertical; two different strains I think. I think you can possibly follow some pedigree lines, one that is known for being rather resistant and then follow any progeny that may retain their parent’s leaves or leaf characteristics.
Rugose leaves on most rugosas do not blackspot. Their resistance becomes a bit diluted when hybridized with others it seems, you loosee that sorta downy surface. The gallicas with their sorta fuzzy foliage do not tend to blackspot either. So downy leaves seem to be less blackspot prone? Perhaps?
I live in Northern California 100 miles south of the Oregon border about 8-10 miles from the ocean. I tend to think our climate is very similar to western Washington’s. I have been growing roses for over 25 years and I am greatly involved with our local rose society. I have been hybridizing (hybrid teas) for at least 15 years and my primary goal is disease resistance. As the years have passed my goals as an amateur hybridizer have changed considerably. At first my goals were form, unusual color, one bloom per stem, vigorous, amazing fragrance, I think you get the picture. Now my primary goal, EXCELLENT DISEASE RESISTANCE. Nothing is more disappointing then growing a beautiful fragrant rose only to have it fall prey to all the known diseases that are out there. Having said this I set out to find hybrid teas with great disease resistance that were grown by our local rose society members. Many years ago a long standing rose grower and friend insisted that I must use Solitaire if I planned to get any good disease resistance in my offspring. Solitaire, in our climate, on a scale of 1-100 is about 90% disease resistant. I spray Banner Maxx once early in the spring and after that I do not spray again. I used Solitaire as the pollen parent for many years (about 300 seedlings) before finally getting a seedling with amazing disease resistance for me. I also tried Solitaire as the seed parent but the low germination rate for Solitaire seeds was not worth all the effort. I am using this excellent disease resistant seedling exclusively as my seed parent and crossing it with some of the new, mostly disease resistant (time will tell) hybrid teas that are currently on the market. I’ve used Dick Clark (grandiflora) and have just purchased Francis Meilland in hopes of improving this disease fighting ability. I also grow a great disease resistant rose (Paddy Stephens, 90% resistance) also a Solitaire seedling, but so far as pollen parent has not produced any seedlings. This seedling of mine has great disease fighting ability (about 95% resistance) and is vigorous, one bloom per stem, nice seed producer but the flower is a simple light yellow rose very similar in looks to the floribunda rose, Sunsprite, and with about 15-20 petals. I am an eternal optimist and the perfect rose is just around the corner (he he he).
Hybridizing take patience and I believe that disease resistance is vital in new rose varieties if we plan to grow roses that are easy and inspiring for the average person to grow.
I hope the sharing of my experience is somewhat beneficial (and inspiring) to all the hybridizers who are working toward their ideal rose.
“Now my primary goal, EXCELLENT DISEASE RESISTANCE. Nothing is more disappointing then growing a beautiful fragrant rose only to have it fall prey to all the known diseases that are out there.”
Same for me, I never spray and growing nice seedlings to see them all defoliated at first outdoor flower is not my aim.
So some fifteen years I quitted breeding HTs and started back from species.
After a few hundred of thousand seedlings the first ones that fit my goals are coming.
Kordes has among the later Europa released HTs a few they rate as 100% BS resistant.
This rating I tend to confirm (I need a second year to be more confident) as foliage is spotless in a climate where i.e. Francis Meilland is not at all.
