Someone else posted about this yesterday. There are several different fungal infections that can be the cause. I put a link in that post with photos, etc. I'd spray these with a fungicide asap. I use Daconcil on mine. They usually have it at Lowes or Home Depot.

In the past I grew about 1000 roses in a northern Ohio zone 5 garden. I did not spray. I would get a little blackspot on some roses late in the season. I have stated that I consider that as possibly part of Nature's way of shutting down the roses for winter. I have posted this information (or something similar) many times on the web: "There is a another choice. This choice is to allow the friendly fungi to reach equilibrium with the blackspot. This choice comes under the heading of "biocontrol". The following may be useful in putting the concept of biocontrol into layman terms: "Disease-suppressive soil microorganisms have been found in many places. In monoculture wheat the severity of "take all" disease often decreases within three to five years. This phenomenon is known as "take all decline," and is considered an effective natural control. Although the mechanisms are not completely understood, the decline is associated with changes in soil microorganisms that compete with and prey on the fungus. Melon plants grown in the Chateaurenard region of France do not show Fusarium wilt symptoms even though the fungus is present in the soil. Soils with suppressive characteristics tend to develop slowly and are usually found in fields where perennial crops or monocultures have been grown for many years. Suppressiveness may be lost if the monoculture is interrupted even for one year, or if pesticides are applied. For example, researchers first recognized soils suppressive to cereal-cyst nematode when nematode numbers increased after application of a broad-spectrum biocide. Many species of fungi and bacteria in the genera Trichoderma, Streptomyces, Bacillus and Pseudomonas suppress diseases, but at this time only a few strains are commercially available. Additional commercial products may be available soon, however, as this is currently an active research area." The quote was taken from: [sorry link no longer works] ------------------------------------------------- A scientific study (2007) of biocontrol of blackspot of roses: http://www.tandfonline.com/doi/abs/10.1080/17429140701701071 --------------------------------------------- " Thread where the above appeared: http://forums2.gardenweb.com/forums/load/rosesant/msg06130420825.html

I took leaves off a badly BS diseased rose bush before and threw those leaves into our Double Ko rose bush all season long to see what would happen...Nothing happened...lol...As far as I'm concerned if a rose bush is truly resistant if will remain clean regardless... Except maybe if a new strain of BS is introduced into the yard that the rose bush is susceptible too ...Or rose bush becomes weakened... BS spores are everywhere regardless of how well we clean up..lol...Just my opinion...lol But if a person feels better by cleaning up then I think they should for peace of mind..

I wonder why mine didn't update! There seem to be a lot of weird things happening on this forum, when I clicked on the 'roses' icon above it didn't take me back to the forum, but to a page that said ' No posts found'.