Gardeners are being urged to use a common kitchen staple to protect their roses from black spot, a fungal disease that thrives in spring. According to Joe, a gardener and founder of In the Wild Garden, a simple milk spray can prevent or combat the condition.
Black spot causes dark patches on rose leaves, which eventually fall off and spread the infection. While it rarely kills roses outright, it weakens the plant, making it more susceptible to pests and other diseases. The fungus is most active when the soil is warm and damp, typical of spring weather.
Joe recommends mixing one part full-fat milk with two parts water in a spray bottle and applying it to the leaves weekly. When exposed to sunlight, milk produces compounds toxic to fungal spores, and it also forms a protective film that prevents spores from attaching to the leaves.
To maximise effectiveness, gardeners should keep the area around roses tidy, removing fallen leaves and debris, and mulch with compost or wood bark to stop spores splashing up from the soil. If black spot appears, strip the affected leaves and dispose of them in the bin, then continue spraying.
Joe advises applying the spray in the evening to avoid the sour smell that develops in hot afternoon sun. However, ensure the plant dries completely overnight to deter slugs and other pests.
