Frankie
Hi, I love roses, I have several. I use the rose dust for mine, it works well. I think they are all poisonous. I remove all diseases leaves and branches. When I have a severe case, I cut the rose right back and let it start anew. I will let you know if I find out a safer one, I am going to dinner at my inlaws next week and she knows a lot about these things. Meanwhile, I looked it up!
Mix a 50:50 ratio of milk and water and spray your roses for black spot and powdery mildew.
Baking soda also works well:
1 TBSP in 1 gallon of water with a few drops of dish soap. Spray on the roses.
Dust the ground around roses with cornmeal, and water in. This helps to eliminate black spot spores that attack roses, and also helps to eliminate the spores in the soil around roses.
Basic Cornell Spray: For Control Of Blackspot & Powdery Mildew: ( for really bad cases):
This was developed by the people at Cornell University for foliar diseases on roses. Do not substitute vegetable oil spray for the summer weight agricultural oil, it doesn't emulsify in suspension when water is added. Another tip is to spray this in the evening, around or just after supper time. Do not spray this in the hottest part of the day.
2tbs Horticultural Oil (Sunspray or Volk Oil)
1tbs of baking soda
Add to 1 gallon of water and spray leaf surfaces LIGHTLY, not to dripping. Reapply every two weeks.
This will help to control powdery mildew and blackspot as well as other fungal diseases on roses.
And at another site, got this...
If you would like to minimize your use of chemical pesticides, you can try spraying your roses with the following baking soda solution weekly. Mix one tablespoon of baking soda with a gallon of water and a few drops of a lightweight horticultural oil. This solution works best as a preventative, rather than as a cure.