The natural method to save roses and hydrangeas from black spot
The most common and severe ailment that impacts both roses and hydrangeas is fungal infection. When it comes to roses, they are highly vulnerable to black spot.
TL;DR
- Fungal infections, particularly black spot, are common and severe ailments affecting roses and hydrangeas.
- Black spot on roses is caused by the fungus Diplocarpon rosae, leading to purple/black leaf markings and early leaf drop.
- Hydrangeas can develop fungal leaf spot, appearing as pale brown markings with darker edges, causing yellowing and leaf loss.
- Gardening expert Caroline suggests using horticultural cornmeal as an organic treatment.
- Horticultural cornmeal, milled from the outer shell of the kernel, contains protein that promotes beneficial fungi which compete with black spot.
- To apply, distribute one cup of cornmeal per large shrub around the base and work it into the soil, watering it in.
- Cornmeal also serves as a fertilizer, weed manager, soil conditioner, and organic fungicide for farmers.
- Using cornmeal eliminates the need for chemical sprays like copper fungicides.
- Mulching after treating for black spot helps nourish soil and roots, and covers fungal spores to prevent re-infection.