Roses can be protected from black spot, a serious fungal disease, by applying diluted milk to the base of the plant every two weeks. The home remedy helps keep foliage green and glossy while also feeding the plants.
Black spot is described by the Royal Horticultural Society (RHS) as the most serious disease affecting roses. It leaves plants covered in dark patches, causes yellowing foliage and can result in premature leaf drop. A severely affected rose can shed a significant proportion of its leaves, reducing the plant's vigour.
Gardeners share milk remedy
On the Gardening Hints and Tips Facebook page, Karen Powell shared a photograph of her flourishing pink rose and explained how she controlled black spot with diluted milk. She wrote: "Here's how your rose will look when you control black spot with diluted milk. Water it at the base every two weeks. It gives nice green glossy leaves. It also helps feed them."
Milk contains natural proteins and enzymes with antifungal properties that can eliminate the spores. It proves most effective when exposed to sunlight, as it creates an environment less conducive to fungus and can form a thin coating that prevents spores from adhering to the plant.
Other gardeners' tips and RHS advice
Other gardeners endorsed the technique, while some suggested using bicarbonate of soda. Lou Deane wrote: "I use my nearly empty milk cartons. Fill them up with water and empty onto the roses at least once a week."
The RHS also recommends a non-chemical approach, which can be started in autumn by gathering fallen leaves. They said: "If practical, pick off and dispose of any leaves that remain on the plant over the winter months. Prune out all stem lesions in spring before leaves appear. These actions will help delay the onset of the disease, but are of limited value because spores are bound to blow in on wind-blown rain from elsewhere."
Keeping black spot under control helps roses remain healthier for longer, allowing them to retain foliage and carry on flowering into early autumn. Good garden hygiene is widely regarded as the most effective first line of defence, so gardeners should remove diseased material, clear away infected fallen leaves and avoid conditions where foliage stays damp for extended periods. Getting the disease under control in autumn is vital to help prevent black spot from re-emerging the following year.
