What is powdery mildew?
Powdery mildew is a fungus which grows superficially on a plants surface. In case of African violet plants, this can be on the leaves, stems, buds or blooms. Patches of powdery mildew can enlarge and in some cases cover a leaf both front and back and entire blooms.
Why do you have to remove powdery mildew from African Violet plants?
To maintain a healthy plant it is important to remove powdery mildew as soon as possible. Powdery mildew is responsible for slowing the growth of the African Violet plants. It can also cause the leaves to yellow, become dry and brown. In extreme cases if powdery mildew is not controlled it can cause plant growth dormancy and make the plant appear extremely unsightly!!
Where can powdery mildew on African Violet plants be found?
Powdery mildew can be found on the outer surface of leaves, stems, buds and blooms. Young new growth of leaves and blooms may be particularly susceptible.
What does powdery mildew on African Violet plants look like?
Powdery mildew looks like patches of white or powdery growth. On leaves and blooms they can look like powdered sugar dusted on them or like white spots or a white substance sitting on them.
Why do African Violet plants develop powdery mildew?
- In the case of African Violets, powdery mildew can develop due to high humidity (hot and humid conditions).
- Overcrowding of plants in a tray can cause powdery mildew due to poor air circulation. This can also lead to neighboring plants being infected too.
- Condensation on leaves due to temperature fluctuations between day and night can also cause powdery mildew (cold and wet conditions).
How to remove powdery mildew from African Violet plants?
- First remove all infected leaves, buds and blooms. Also remove all the remaining healthy buds/bloom stalks too. Second, water the plants well.
- For plants with a light coating of mildew or first signs of mildew, use a Q-tip dipped in 50% diluted solution of rubbing alcohol with water to gently wipe the mildew away. Make sure to treat the leaves underneath surfaces too.
- Other treatments methods include (always use tepid water):
- One tbsp baking soda, half tsp liquid soap and One gallon of water.
- One: nine parts organic milk mixed with water.
- One capful of Lysol mixed with 500ml of water.
Remember not to spray very close up on the plant, spray in the air from a distance so the solution gently falls onto the plant.
- If the natural methods are not effective, spray diluted organic neem oil or a commercial fungicide over the plant foliage. Please follow exact directions on the container.
How to prevent African Violets from developing powdery mildew?
- Ensure basic routine care of African Violets to prevent development of powdery mildew.
- Routine grooming of the African Violet plant, i.e. removing dead, dried, yellow leaves and dried blooms can ensure that it maintains good growth.
- Make sure the plant stands and surrounding areas are clean..i.e. the plant tray, tray lids, pots, tools and watering cans/containers are all clean and disinfected twice a year with a diluted bleach solution (1:9 bleach: water ratio).
- Space plants out evenly to ensure good air circulation, do not over-crowd.
- Purchase only disease free plants, inspect them well before purchasing.
- During hot summers use a fan to promote air circulation.