Help with Tea Roses

So I need some help with my tea roses. I have had a small rose garden for about 2 -3 years. This last winter I cut them back and mulched them with wood mulch. This year I have lost about the bottom half of my leaves. I thought I saw an article that Shelley had posted at one point related to black spotting on the foliage. I can not find that article so I am wondering if this is related to a disease and what I might be doing wrong. Is it possible that all this moisture of the last two summers is causing some type of mold? Or could it be the wood mulch causing this effect? Any information or direction you all can give me related to this problem and general rose care would be great. My wife loves the roses and I love being able to cut fresh roses for her. Also, I have several red and pink roses but any suggested hearty varieties for white or yellow would be appreciated.