- Black spot disease, caused by the fungus Diplocarpon rosae, is a common and often fatal threat to roses, leading to black spots on foliage, diminished blooms, and weakened plants.
- Effective management involves pruning and disposing of all infected leaves and branches in sealed bags to prevent reinfection, avoiding humid conditions during this process.
- Fungicides containing mancozeb are highly effective for treatment, while environmentally friendly options include Neem oil and copper fungicide, applied after initial clean-up.
- Preventive measures for future seasons include applying fungicides like Neem oil or potassium bicarbonate in spring, using a baking soda solution, or companion planting with onions or tomatoes.
- Best practices such as ensuring adequate plant spacing for air circulation, deep watering at the roots with a soaker hose, and selecting disease-resistant rose varieties are crucial for long-term prevention.
IN FULL
How to treat roses with black spot disease – and protect them from infection
