Image source: Enzie Shahmiri
I have a lot of roses in my garden and try to stay vigilant about clipping off any leaves that show the slightest signs of disease. Sometimes I can catch the problem in time and at other times sadly black spot or mildew get the upper hand.
In search for a better solution I came across an interesting article on
about using Chamomile tea will help plants that suffer from fungus or mildew.The author suggested this:
Place 16 chamomile tea bags (or 2 cups of dried chamomile flowers) in 2 quarts of water, and simmer for 20 minutes. Turn off the heat, and allow the tea bags to steep for several hours. Strain, if using dried flowers. Use the tea to irrigate tender seedlings (from the bottom) to prevent damping off, or use as a foliar spray to battle diseases on plants. "
You can also mix 2 teaspoons of baking soda and 1/2 teaspoon of liquid soap or Murphy's oil soap in 2 quarts of water and then spray the plant, which helps to protect the roses for months.
Baking soda and oil: The baking soda changes changes the pH of the black spot, effectively killing it.
1 gallon water, 3 tsp baking soda, 1 tsp canola oil. Mix and apply mixture weekly. Be aware that spraying roses on hot sunny days may cause the leaves to "sunburn."
Milk and Water: The milk changes the pH of the fungus and kills it.
Make a mixture of one part milk, two parts water. Spray weekly.
Neem Oil: Neem oil is made from the evergreen Neem tree. The oil is an effective antifungicide and is commercially available in many garden centers.
The Neem oil works by preventing the formation of the black spot fungus spores. Neem oil comes in different strengths, so mix according to the bottle's directions.
Be cautious about spraying Neem oil on leaves which get many hours of full, midday sun as sunburn can occur.