All of our Roses have lost all of their leaves starting in late June. I also motice this has happened at another yard across town. I could find no sign of insects or disease, there has been adequate water, and the plants bloomed normally earlier in the year. Need help here, please.
There is one exception. hybrid musk, 'Ballerina' remains normal. The leafless ones are floribunda, 'Poulsen's Pearl', and grandiflora, 'Queen Elizabeth'.
Same here in my garden. Eglantyne and the climbers "Parade" and "America" are nearly bare. There is some blackspot, but that does not seem to be the problem as the leaves yellow and drop even without black spot. The problem started soon after the start of the recent hot spell - I suspected that being a factor. Like yours, our planst are consistently watered. I could not find any evidence of spider mites, which could be the other likely culprit. The rest of roses are fine, even the ones adjacent to the leafless roses.
You might see if you can find something here. http://www.extension.umn.edu/projects/yardandgarden/diagnostics/rose.html
I guess in the case of the leafless roses in our garden, it must have been the heat. Now that it has cooled down, I am seeing lots of young new laterals sprouting all over the place.
