Sulpher is the most effective organic fungicide. It too has to be sprayed as a preventative, as that is how any fungicide works. From your list of climbers on the other thread though, I really think that thinning the herd is the way to go if you want to be organic. None on your list is in any way particularly resistant to disease, and fighting this fight with those roses is going to leave you frustrated. Or, really research (not the hearsay studies often posted on this forum) non organic methods of disease control which will allow you to keep your current roses. Not everything "organic" is safe, nor is everything "chemical" unsafe. Many of the newer high tech chemicals require less per dose, less often spraying, and have a much safer profile. It's all in the products you choose. Below is a scientific based site that gives you informatinon a wide variety of chemicals.

Here is a link that might be useful: Extonet

HollySprings: Hey, thanks for the link. I've put it in my Favorites and will spend some time there---looks useful for things other than gardening as well. You know, I had been using the sulfur as a dormant spray (or actually my 1st spray in Feb. after pruning)but a local rose society guy has been insisting that dormant spraying is a waste of time. I'll go back to it...

Once they are covered in blackspot, there is nothing organic or non-organic you can do. The key to control of blackspot is to spray before you see it. The goal is to prevent it, because you cannot reverse it once it hits. If you start spraying something now (organic or non-organic), it will protect the new leaves that are growing.

A lot of people claim that vinegar works wonders on heavy blackspotted bushes. Here's an old thread discussing it. It's worth a try...... :))

Here is a link that might be useful: vinegar for blackspot