HELP am I killing my roses or is my neighbor
I recently moved to a home that has 6 rose bushes. 4 of them have black spot. 3 have a mild case and one has a very severe case. On the advice or a nursery, I began the process of removing all the affected leaves. I started with the worst bush and after removing all affected leaves, only 5 leaves remain on the entire bush. I immediately felt a huge amount of remorse, feeling that this couldn't possibly be enough leaves for adequate photosynthesis. This same nursery told me to spray neem oil after removing the affected leaves, but my internet research informs me that neem oil interferes somewhat with photosynthesis, so I'm afraid to use it on this now-fragile plant. I called another nursery which said to do absolutely nothing to this plant until it has more leaves. A third nursery told me to use Bayer systemic on all my plants and the problem will go away. I'm a bit nervous about applying chemical sprays, so I started looking for alternatives on gardenweb which is where I heard about cornmeal usage. It sounded a bit unusual, but certainly the least invasive method I've heard of so far. I've decided that I don't care if my leaves have a few black spots on them. I'm not after perfection. But I do want to save this rose bush and have healthy blooms but I don't want to have to wear a respirator to achieve this state. Any suggestions? By the way, my neighbor waters her bushes in the afternoon with a spray hose and a fair amount of water gets on the rose bushes--could this be what's spreading the black spot? I hate to confront her unless it's absolutely necessary. The nursery said that her watering practices won't harm my roses because black spot is caused by poor soil conditions, so they say that I must improve my aerate my clay soil and fertilize. I'm guessing that I can't aerate the soil until the winter when the plant is dormant and I would then have to remove the plant to do so? Also I drip irrigate them at 5a.m.every day because they are on the same system as plants that need frequent watering--but am I harming the rose bushes by doing that? Your advice before I screw this up even further would be much appreciated.