Rose Black Spot
21 Aug, 2021
The fungus thrives in humid conditions. Reduce likelihood of black spot becoming a problem by increasing airflow around plants (by pruning, weeding, not crowding plants), and by avoiding wetting the stem when you water.
Spray ornamentals and roses with Combat 3-in-1 for Roses.
In severe cases treating with Super Shield may be more effective.
Spray plants with Liquid copper over winter to help protect the plant. Pick off affected leaves, and sweep up and take away affected foliage from around the plant.