Red and black spots appear on camellia leaves. Is it anthracnose or spider mites? How to solve it?

The appearance of red and black spots on camellia leaves is a disease of the plant, not spider mites. Judging from the pictures provided by the subject, it should be anthrax and soot disease, and there are traces of drug spots on it. It is estimated that there is not much effect after the treatment. Below I will explain how to solve this problem based on my experience in growing camellias.

1. Causes of camellia anthracnose (red spots):

1. Generally, the room temperature is between 25℃-28℃. If there are continuous rainy days, watering is not necessary. Note that overwatering can easily cause anthracnose.

2. It usually occurs during the rainy season or spring when continuous rainfall occurs.

2. Solutions after anthrax occurs:

1. Pay attention to adjusting the room temperature and ensure that windows are opened for ventilation.

2. Cut off yellow leaves, diseased leaves and dead branches promptly.

3. To prevent the disease before onset, you can spray Bordeaux mixture or carbendazim for prevention and treatment.

4. Be careful not to water too much at ordinary times. Keep the pot soil dry before watering appropriately. In addition, potassium dihydrogen phosphate can be added appropriately to promote flower bud differentiation and leaf re-growth.

3. Causes of camellia soot disease (black spots):

1. Affected by climate environment and rainy days.

2. If the pruning is not timely, the whole plant will have poor transparency and lighting.

3. The secretions left by some pests serve as pathogens and provide nutrients for bacteria to spread.

4. Solutions to camellia soot disease:

1. Prune appropriately to reduce the number of diseased branches and leaves and improve the transparency and lighting of the entire plant.

2. In the early stage of the disease, thiophanate methyl wettable powder, chlorothalonil wettable powder, chlorothalonil wettable powder, 0.3% to 0.5% Bordeaux mixture, etc. can be used for prevention and control. Apply the medicine twice a day, spraying once every 10 days or so. Completely nip sooty disease and anthrax in the cradle.

Based on the above two camellia diseases, from the perspective of the most economical cost, I suggest that the subject use Bordeaux mixture for comprehensive control. One medicine cures two diseases, but later management must also be strengthened, especially pruning.

The above are some of my suggestions on camellia anthracnose and soot disease. I hope it will be helpful to you. If you have more questions about maintenance, you can leave a message in the comment area, and we can discuss it together.