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How to Cure Black Spots on Plants

Black spots on plants are caused by a mixture of fungus and bacteria that can spread and kill a plant. Most commonly the fungal disease appears on the leaves of miniature roses, where the black spots turn yellow and the leaves fall off. The black spots can also spread and create purple spot on the stems of the flowers, causing the entire flower to die. Curing the black spots depends on how far the disease has spread on the leaf. However, it’s still important to treat the leaf and entire flower to prevent the disease from spreading further.

Add 3 Tbsp cider vinegar and 1 gallon of water into a bucket and stir thoroughly. Pour the mixture into a spray bottle.

  • Black spots on plants are caused by a mixture of fungus and bacteria that can spread and kill a plant.
  • Curing the black spots depends on how far the disease has spread on the leaf.

Spray the mixture onto the black spots. Make sure that you only spray the leaf and not other parts of the plant. Let the mixture sit for at least five minutes before continuing.

Wipe the entire leaf with a paper towel. Make sure that you wear latex gloves when doing this. Wipe two or three times and see if the black spot still remains. Apply the mixture again to the leaf if the black spot is still there, and then wipe the leaf again after five minutes.

  • Spray the mixture onto the black spots.
  • Apply the mixture again to the leaf if the black spot is still there, and then wipe the leaf again after five minutes.

Cut of the leaf with a sharp knife or gardening scissors if the black spot cannot be removed using the vinegar and water mixture. Dispose of the leaf and rake up any other fallen leaves.

Continue using the solution to remove any more black spots that appear and remove any of the diseased leaves if necessary. It’s best to act immediately so that the disease doesn’t spread throughout the plant.

Cure Black Spots On Plants

Black spots are among the most common symptoms of plant disease, whether the problem is a fungus or a bacterial infection. Always begin by researching the common diseases of the plant species. It's important to reach a define diagnosis before you attempt to treat the plant. Examine the plant for other disease symptoms known to be associated with black spots on the species. Look over canes for the presence of purple-hued areas of dying plant tissue. Examine trees that lose their leaves early for distorted branches. Regularly monitor vegetable crops such as tomatoes. Look for blight issues, such as early blight, caused by the fungal pathogen Alternaria solani, which causes black spots in the form of a bull's eye on lower leaves. Use pruning shears to remove affected plant parts, and destroy the removed material, including fallen debris. Overhead irrigation causes standing water on leaf surfaces, which can provide the ideal environment for proliferation of both fungal and bacterial pathogens. Put a 2- to 3-inch layer of organic mulch such as wood chips under surrounding plants without pressing it against stems or trunks. Saturate roses with neem oil or a sulfur-based pesticide, for example. Apply fungicides with chlorothalonil to plants affected with anthracnose at bud break, and again in two weeks in the case of wet weather; apply to blighted vegetables as well, before symptoms occur and during active growth.

  • Cut of the leaf with a sharp knife or gardening scissors if the black spot cannot be removed using the vinegar and water mixture.
  • Overhead irrigation causes standing water on leaf surfaces, which can provide the ideal environment for proliferation of both fungal and bacterial pathogens.
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