The reason why the leaves of coleus turn black

1. Infection

Cause: The leaves of coleus turn black, which may be caused by gray mold, which can harm the leaves. At first, there will be water-like spots on the leaves, which will gradually expand and turn brown or black, giving a feeling of soft rot and making them easier to identify. Measures: This disease is mainly prevented. Pay more attention to ventilation and promote air circulation. Apply less nitrogen fertilizer during daily maintenance and management. After the disease occurs, remove the rotten leaves in time, and then spray with pesticides such as Shijiale and Botrytis cinerea.

2. Strong light burns

Reason: Coleus likes sunlight, but cannot withstand strong light. Once exposed to strong light, the tips of the leaves will turn black, seriously affecting its ornamental value. Measures: Cut off the blackened parts, then change the maintenance environment and place it in a cool, diffused light place for maintenance.

3. Too much dust

Reason: If the leaves are not managed for a long time, a lot of dust will accumulate on the leaves, which will affect photosynthesis and may also breed bacteria and cause the leaves to turn black. Measures: Remove the dust in time and wipe it gently with a rag dipped in water.

4. Low temperature

Reason: It cannot tolerate low temperatures. If the temperature is low, the leaves will turn black. Measures: Keep warm in winter and the temperature should not be lower than 10 degrees Celsius.

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