There is probably no really effective organic control for black spot. Hybrid
tea roses & their ilk require a lot of chemical controls. I use Rose and Flower
granules for systemic insecticide, which avoids insecticide spraying, but you
just have to spray for black spot. It is not that dangerous if you just keep
the kids & the pets away while you are actually spraying. If you are too
fearful, grow something else.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)