Black mold on orchids

Black mold on orchids is a serious issue that can arise due to high humidity, poor ventilation, or fungal spore infection. It can affect leaves, roots, substrate, and even flower spikes. If not addressed promptly, mold can weaken the plant and potentially lead to its death.

Causes of black mold

1. Overwatering:
   • A constantly wet substrate creates ideal conditions for fungal growth.
2. Poor ventilation:
3. Lack of airflow around the plant promotes moisture buildup and mold growth.
4. Compact and decomposed substrate retains water and becomes a source of infection.
5. Mold can spread from other contaminated plants.
6. When humidity levels exceed 70% and there is no air circulation, mold proliferates rapidly.
7. Old or decomposed substrate:
8. Contact with infected plants:
9. High humidity:

What to do if black mold appears?

1. Remove the mold

• From leaves and flower spikes:
  • Wipe the affected areas with a cotton pad soaked in fungicide solution, hydrogen peroxide (1 tablespoon per 1 liter of water), or a mild soapy solution.
• From roots:
• Remove the plant from its pot, rinse the roots under running water, and cut off the affected areas with a sterile tool.
• Replace the substrate entirely with fresh materials, as the old one likely contains fungal spores.
• From the substrate:

2. Treat with fungicide

• Use specialized orchid treatments such as "fundazol" or "fitosporin."
• Dilute the fungicide according to the instructions and treat the entire plant, including roots, leaves, and substrate.
• Repeat the treatment in 7–10 days to prevent reinfection.

3. Wash the roots

• Soak the orchid’s roots in a solution of potassium permanganate (light pink) or hydrogen peroxide for 10–15 minutes.
• Allow the roots to air-dry before repotting.

4. Repot the plant

• Prepare a new substrate made of pine bark, coconut chips, or sphagnum moss.
• Use a pot with drainage holes to prevent water stagnation.
• Ensure the plant is placed in a well-ventilated area after repotting.

Preventing black mold

1. Control watering

• Only water the orchid after the substrate has completely dried out.
• Use transparent pots to monitor root and moisture levels.

2. Ensure proper ventilation

• Place the orchid in a well-ventilated area.
• Use a fan or humidifier with air circulation functionality.

3. Replace the substrate

• Change the substrate every 1.5–2 years.
• Opt for high-quality, breathable materials.

4. Maintain moderate humidity

• Keep air humidity levels at 50–60%.
• Ventilate the room regularly if humidity levels are high.

5. Preventative treatment

• Spray the plant once a month with a fungicide solution or a biological treatment like "fitosporin."

6. Isolate new plants

• Ensure new plants are healthy before placing them near your other orchids.

Conclusion

Black mold poses a significant threat to an orchid’s health, but it can be eliminated with prompt and effective measures. Removing infected areas, treating with fungicides, and improving care conditions will help save the plant and prevent mold from reappearing. Regular care and preventative measures will ensure your orchid thrives and stays healthy for a long time.