One of the most common houseplants, African violets are loved not only for their beautiful appearance but also for their relative hardiness. It’s usually pretty easy to care for African violets, at least compared to many other houseplants. However, this doesn’t mean that African violets aren’t sometimes susceptible to disease and fungus just like any other plant.
The good news is that African violets don’t fall prey to disease and fungus too often, but if disease or fungus develops on your African violet, then you need to know what to do next.
Some, but not all, of the most common diseases African violets face can be treated. Sometimes it does take a good bit of extra care and attention, though. It’s also possible to prevent your African violet from being exposed to disease and fungus in the first place.
Keep reading to find out how you can protect your African violets from disease and fungus, and what to do to treat your African violets if these problems arise despite your best efforts.
Powdery mildew is a common fungal disease that can affect many plants, including African violets It manifests as a white, powdery coating on the leaves, stems, and flowers While not typically fatal, powdery mildew can significantly impact the health and appearance of African violets if left unchecked. In this comprehensive guide, we’ll cover how to identify, treat, and prevent powdery mildew on your beloved African violets.
What Causes Powdery Mildew on African Violets?
Powdery mildew is caused by fungal spores that thrive in warm, humid environments with poor air circulation. Fluctuations in temperature and low light exposure can also contribute to outbreaks. The spores germinate on the plant’s surface and send rootlike growths called haustoria into the plant’s cells, from which they leach nutrients. The fungus then covers itself with the iconic white “powder” – actually chains of spores – which allows it to spread quickly to surrounding leaves and plants.
How to Identify Powdery Mildew on African Violets
Powdery mildew is easy to recognize on African violets. Watch for these key signs:
- White or gray powdery coating on leaves, stems, and/or flowers
- Powdery coating starts off patchy but spreads to cover entire affected areas
- Leaves yellowing or browning
- Flowers dropping off
- Slowed growth
- Spots or streaks on flowers
Carefully inspect both tops and undersides of leaves as well as stems and flowers to check for the distinctive powdery fungus. Powdery mildew can sometimes be confused with botrytis, another fungal disease, so note that powdery mildew has a fine, uniform texture compared to botrytis’ fuzzier, spotty growth.
Treating Powdery Mildew on African Violets
If you catch powdery mildew early, treatment can help restore your African violets’ health. Here are some effective powdery mildew treatments:
-
Isolate affected plants to prevent spread Discard severely infected plants
-
Improve air circulation with fans; avoid overcrowding.
-
Trim off badly affected leaves and flowers. Remove debris carefully to avoid spreading spores.
-
Wash leaves gently with water to remove spores. Avoid wetting foliage.
-
Apply neem oil, milk, vinegar, hydrogen peroxide, or baking soda solutions to leaves and stems. May require multiple applications.
-
If needed, use commercial fungicides containing sulfur, neem oil, or chemicals like benomyl or captan. Follow label directions closely.
-
Maintain warm, stable temperatures around 70°F to discourage fungal growth. Avoid drafts and temperature shifts.
-
Reduce humidity to 60% or below.
-
Improve light exposure if low light is an issue.
With vigilant treatment, you can get powdery mildew under control and restore your African violets to health. Be sure to continue preventive care.
Preventing Powdery Mildew on African Violets
While powdery mildew treatment can be effective, prevention is always better to avoid stressed, damaged plants. Here are some key powdery mildew prevention tips for African violets:
-
Site plants properly – ensure good air circulation, avoid high humidity and overcrowding, maintain consistent warm temperatures around 70°F.
-
Water carefully – don’t splash leaves, allow pots to dry out between waterings.
-
Ensure adequate light – African violets need 12-14 hours of bright, indirect light daily.
-
Remove spent flowers/leaves – prune promptly to improve air flow.
-
Disinfect pots, tools – use a 10% bleach solution to kill lingering fungal spores.
-
Use fans judiciously – gentle air circulation helps prevent fungal and bacterial diseases. Avoid drafts.
-
Limit high-nitrogen fertilizer – promotes fast, weak growth prone to mildew. Moderate feeding with balanced fertilizer.
-
Isolate new plants – quarantine and monitor for diseases before introducing to your collection.
-
Scout regularly for problems – catch powdery mildew early before it spreads.
With proper growing conditions and care, you can help your African violets thrive and avoid powdery mildew issues. Be vigilant for early signs and take prompt action at the first hint of powdery growth. Stay on top of prevention, and you can continue enjoying the unique beauty of healthy African violets.
Cross-Contamination With New Plants
If you’re providing good care for your African violets, it’s unlikely that disease and fungus will develop. However, there is a risk of introducing disease and fungus anytime you bring new plants into your home.
Carefully inspect any plant, African violet or otherwise, before bringing it into your home with the rest of your African violets. Once a disease or fungus passes on to other plants, it can be difficult to stop the spread and save your plants. Do not bring any plant that shows signs of disease or fungus into your home.
Some people even go so far as to keep new plants in a separate area for a period of time just to make sure everything is fine. While this may seem excessive, if you have a large plant collection or plants that would be difficult to replace, it makes sense to quarantine any new plants before placing them with the rest of your collection.
African Violet Diseases Final Thoughts
Although there are a lot of diseases that can bother African violets, most of these diseases don’t occur too frequently (with the exception of ring spots, which are easy to avoid).
Take good care of your African violets to prevent disease and fungus from developing in the first place. As a quick reminder, here are a few of the best ways to keep your plants from having problems:
- Don’t overwater your African violets. Let the soil dry out between waterings.
- Keep your tools and containers sterilized.
- Make sure your African violets have adequate air circulation.
Also, carefully inspect any new African violets and isolate them to watch for signs of fungus or disease before bringing them into your home with other African violets.
Hopefully you won’t ever have to deal with diseases infecting your African violets. If you do have an African violet develop a disease, make sure to isolate it right away and keep it isolated while you treat the disease.
If you aren’t able to save an African violet that’s been infected, don’t feel too bad; all houseplant owners lose a plant from time to time. On the bright side, you’ve learned more about what not to do in the future, and you now have room to add another plant to your collection
African Violets – POWDERY MILDEW – Symptoms, Treatment, Prevention
FAQ
How to treat powdery mildew on African Violet?
Simply brush off the mildew with a wet brush, cleaning the brush in methylated spirits after finishing and allowing it to dry. Wash the leaves with mildly warm running water (only in the early part of the day). Blot left-over water away from the centre of the plant.
What kills powdery mildew immediately?
Potassium Bicarbonate:
Similar to baking soda, this has the unique advantage of actually eliminating powdery mildew once it’s there. Potassium bicarbonate is a contact fungicide which kills the powdery mildew spores quickly. In addition, it’s approved for use in organic growing.
Can a plant with powdery mildew be saved?
Luckily, there are effective powdery mildew treatments that can help fight the disease. Powdery mildew can be treated early on with fungicides including potassium bicarbonate, neem oil, sulfur, or copper. Home remedies like baking soda and milk can work as successful treatments when applied properly.
What causes white powder on African violets?
Powdery Mildew is caused by the Oidium fungus which thrives under conditions of high humidity and poor air circulation, especially after sudden changes in temperature. Such conditions often occur in spring when precipitation is high, and hot days alternate with cold nights.