I think the cause would not be the mulch, but the spring weather patterns, combined with having susceptible varieties.

Cornell mixture (oil and baking soda, see the FAQ) would be somewhat more effective against powdery mildew than sulfur. Apply it at bud-break and then as needed until the first-flush foliage hardens up. The only organic control I know of for Botrytis would be a copper product, applied to the buds when the sepals split and then every few days through the first flush. A Windex-type spray bottle would be appropriate (and rubber gloves). Another approach would be to discard the varieties most prone to balling and replace with varieties you've observed to do better in your climate. Or, since you have a long season of many flushes, just ignore the problem.

Hi MichaelG, I will defintely change my spray for powdery mildew to baking soda and oil, very helpful.
I have close to 100 varieties, botyrytis had spread to every rose except if I remember from a year ago, just a few were untouched.
I haven't had any botrytis in the 5 or so years I have been gardening, it seems odd to suddenly have an epidemic like this. Maybe it is just the conditions were perfect for it in someway.
I am going to try and stop the spead of this fungus because spring is a very enjoyable time, the best flush!
so I will implement the copper spray idea, also very helpful. Thank you!

Bordeaux mixture is an acceptable product in most organic gardens, and it will prevent botrytis if sprayed on the rose canes at bud break (pruning time).

Field,
Is the product by HyYield called "copperas" the type of Copper that you're talking about? That's all I can find locally.

Copperas is hydrated ferrous (iron) sulfate, an iron supplement and pH control. Keep asking for Bordeaux Mixture. (It's made from copper sulfate and lime.) You'll find it somewhere because it's a standard nursery and garden center product.

Thanks, Field!

Found it, finally! Was looking for a 2# bag, they had it in a 16oz. can. Yea!