How To Treat Powdery Mildew On African Violets

Our African violets start to develop powdery mildew at this time of year. Because the spores are always in the air, this fungal disease is practically inescapable. However, you can lessen the impact the issue has on your plants. You will be able to identify powdery mildew when the leaves and flowers are covered in a white powdery substance, as in the pictures. On dark flowers, it consistently stands out more. Powdery mildew also affects many different plants, both indoor and outdoor.

When the nights are cool and the days are warm, it appears on the African violets’ leaves and blossoms. Additionally, when the humidity is low, you are more likely to observe it. The correct circumstances also seem to be created by stagnant air, therefore you might be able to increase ventilation by using a fan. There are particular plants that undoubtedly seem to be more vulnerable to powdery mildew and should be closely monitored. Whatever else you decide to do, it is important to cure it as soon as it shows up since, if you don’t, leaves could become scarred and blossoms could be ruined. If you can increase the humidity, do so, even if it just means keeping plants that are sensitive to powdery mildew in a translucent container that resembles a terrarium.

You’ll need some alternatives for addressing the issue whenever it manifests itself. Despite the fact that it is frequently simpler to use a prepared solution, you might avoid using chemical pesticides because powdery mildew only becomes a problem when the right conditions are present.

Why not employ one of these simple techniques:

Simply use a damp brush to scrub away the mildew, allowing the brush to dry after cleaning it in methylated spirits.

Cleanse the leaves with running, lukewarm water (only in the early part of the day). Remove any excess water by blotting it away from the plant’s centre.

Simply heat some water in a mist sprayer, then sprinkle the plants until the water starts to flow off. Don’t leave water pools on the leaves, especially in their centres, once again.

Here are several straightforward organic sprays that are safe to use if you must spray:

One teaspoon of laundry bleach in one litre of water should be sprayed (kills the fungus spores). Many people use this control when growing African violets.

1 teaspoon of bicarbonate soda in 1 litre of warm water should be sprayed. By altering the pH of the leaf surface, the fungus is eliminated. Others advise adding half a teaspoon of insecticidal soap. Some advise using a few drops of liquid soap. This formula has been tried and tested both plain and with soap.

Spray with a milk and water mixture. The suggested strength ranges from a 10% solution to a 40% solution. Although I haven’t personally utilised it, I believe you’d need to do some testing. It was always believed that full-cream milk was necessary, but current thinking holds that proteins do the task instead. Natural enzymes create an environment where mildew cannot develop. Whether you use full-cream or skimmed milk is entirely up to you. I haven’t tried it since I’m afraid of the smell of sour milk, but others have and they say the smell isn’t an issue.

It is possible to combine the milk solution and bicarbonate soda to create a spray, though I’m not sure why you would since either is useful on its own.

Spray 1 litre of water with 1 teaspoon of vinegar. rumoured to destroy the fungus and alter the pH of the leaves.

Sulphur preparations, including powdered sulphur, have long been advised, however African violets should not be exposed to residue on the leaves. Brushing the leaves with sulphur powder will at least temporarily solve the issue. It is a laborious task at best to keep brushing until all of the sulphur has been removed. Powdery mildew was once thought to be easier to manage if plates of powdered sulphur were scattered around around the plants. I’m not sure how much assistance it provides, but I still do it myself because it’s simple to perform and doesn’t hurt. It’s interesting to me how frequently tiny gnats and other unidentified flying creatures commit suicide in the sulphur.

Cinnamon is claimed to be effective against fungus. I believe it would need to be sprayed on the leaves, but the thought of having to remove it from the hairy leaves afterwards makes me shudder. worse than with sulphur.

There have been several more organic type restrictions proposed. Undoubtedly, a simple Google search would turn up a tonne of them. However, it is important to keep in mind that powdery mildew appears to be caused by several fungal species in various plant types. With African violets, what works for one variety of plant might not (or might!) work. You could even develop your own organic powdery mildew remedy for plants. If so, give it a shot on a few violets. Some of those cited include: Tea produced from compost that has been soaked in water and then drained. It is thought to contain healthy organisms. Two whole bulbs of garlic should be grated, then the mixture should be strained and some liquid soap added. Per litre of water, use two to three teaspoons. I would once more be concerned about smell. Keep in mind that none of these sprays can guarantee a permanent solution to the issue. Include the stems and the area under the leaves while spraying the plant. Additionally, you should always test a new spray on a few test plants before using it on your entire collection. Spraying might be necessary every week.

Still intend to utilise a legitimate store-bought spray? Try neem oil diluted as directed. Do you only favour a true fungicide? I consider Yates Fungus Gun to be one of the greatest products now available for ease of use and successful results with African violets.

Keep in mind that African violet powdery mildew is a temporary but persistent issue. All will be well when the circumstances alter till the next time.

How quickly can powdery mildew be eliminated?

Keeping your garden’s air moving enough will help prevent powdery mildew.

According to the volume of inquiries I receive each summer on the powdery mildew plant fungus, I’ve discovered three things over the years: it’s common, you don’t like it, and you want to know how to get rid of it. So, here’s what you need to know to stop it from happening in the first place, manage it, and even get rid of it.

One of the most pervasive and readily recognisable plant fungal diseases is powdery mildew. Almost no plant is immune, from vegetable gardens to rose gardens, ornamental trees, and shrubs.

Don’t be alarmed if you discover that any of your trees or plants have powdery mildew. Because this fungus is host-specific, it doesn’t necessarily mean that other types of plants in your landscape are in danger just because you detect it on one variety of plant. Despite the fact that powdery mildew has numerous species, all of its symptoms are rather uniform.

Most certainly, you’ve seen it before. Powdery white or grey patches develop, frequently covering the majority, if not the entire leaf surface. Additionally, fruit, flowers, and plant stems can all contain it. Fortunately, the harm caused by powdery mildew is typically worse than its symptoms. It rarely kills the plant.

The plant may prematurely defoliate as a result of advanced stages, which can cause the leaf to yellow, curl, or turn brown. The fungus can cause early bud drop or reduced bloom quality on trees and flowering plants.

Dry foliage, high humidity, low light, and moderate temperatures are all factors that encourage mildew growth. Proactive measures to steer clear of or reduce this risk include:

Look for kinds that are disease-resistant. For information on specific cultivars and varieties, get in touch with your county extension service.

Plants should be placed where they will receive at least six hours of light per day. Reduce the amount of shade and prune any light-blocking trees and shrubs.

Refrain from overfertilizing. Fresh growth is more prone. Apply a slow-release fertiliser in its place for more carefully regulated growth.

Early detection is the greatest approach to contain and maybe get rid of the issue if you need to respond to a powdery mildew condition that already exists. There are numerous commercial goods that are successful at keeping the spread under control. However, solving an existing issue is not always a guarantee.

Most conventional products are designed for prevention and control, not for the eradication of an infection that has already taken hold. For this reason, it’s crucial to begin a control programme before powdery mildew appears, or at the very least, at the first indication of detection.

For the treatment of mildew, numerous over-the-counter, retail fungicide treatments are available. “Chlorothalonil” is one of the most often utilised active components for control. Despite being effective, it leaves a clear white milky film on the leaf surface.

Less popular choices include:

The most well-known of the natural, homemade remedies for powdery mildew is probably baking soda (sodium bicarbonate). Studies show that using baking soda alone is not particularly effective, but when combined with horticultural grade or dormant oil and liquid soap, efficacy is quite good if used early on or before an outbreak develops.

Utilize this formula to create your own remedy.

To a gallon of water, add one tablespoon of baking soda, one teaspoon of dormant oil, and one teaspoon of liquid soap (not detergent) that is insecticidal. Every one to two weeks, spray your plants.

bicarbonate of potassium This has the distinct advantage of actually getting rid of powdery mildew once it’s there, much like baking soda does. A contact fungicide called potassium bicarbonate immediately kills the powdery mildew spores. It is also permitted for use in organic farming.

If mouthwash is effective at killing oral bacteria, powdery mildew fungus spores can’t hope to compete. And that is the basic idea. Generic mouthwash with an ethanol basis has a high degree of controllability. Jeff Gillman, a Ph.D. and Associate Professor at the University of Minnesota’s Department of Horticulture, found that tests using one part mouthwash to three parts water performed well. Just be cautious while combining and applying mouthwash because you don’t want to harm fresh foliage.

VinegarVinegar contains acetic acid, which works similarly to mouthwash in controlling powdery mildew. A gallon of water mixed with two to three teaspoons of regular apple cider vinegar (5 percent acetic acid) works well. Although larger amounts (over 5%) of vinegar are more beneficial, too much of it might burn plants.

Lime with Sulfur/Sulfur

Direct contact with sulphur stops the growth of disease spores. The solution will penetrate leaves for even greater efficiency when combined with hydrated lime. The Bordeaux mix, a widely used variant of this mixture, consists of copper sulphate and hydrated lime. All of these remedies have the potential to burn plant tissue, harm soil microbes, and kill beneficial insects. It is also regarded as having a mild toxicity to humans and mammals. If at all, use with caution and sparingly.


Milk is the newest participant in the conflict with powdery mildew. It is thought that naturally existing components in milk are at work to fight the disease while also bolstering the plant’s immune system. The exact reason it works so well is yet unknown. One trial that used a weekly dose of one part milk to two parts water produced positive outcomes.


Ironically, dry weather and high humidity are ideal for the growth of powdery mildew. Straight water, however, works against it because it washes the spores away before they have a chance to implant. However, I do not advocate the use of water as a control measure because moist foliage is a friend to numerous other plant diseases. If you decide to use this strategy, do it early in the day so that the foliage has time to quickly dry off.

Hemp oil

This is a convenient organic alternative for disease and insect control. The neem tree, which is indigenous to India, is used to make neem oil. This natural pesticide has a broad spectrum, is excellent at controlling disease, and is less harmful to mammals and helpful insects. The best method for preventing powdery mildew has mixed results. Results are often at best average.

Even with a wide range of management options, prevention remains the best treatment for diseases like powdery mildew as well as other conditions.

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What causes African violets to get powdery mildew?

A fungus causes powdery mildew in African violets (Oidium species). The powdery spots are made up of spores and fungal filaments. The spores are transported by air currents to the same plant’s healthy leaves and blooms as well as to other African violets. The fungus deprives the plant of its nutrition, resulting in tissue yellowing or browning. Powdery mildew thrives in low light, warm weather, and cool nights.

Why is my African violet covered in white material?


My African violet plants have some white spots on their leaves. What exactly are they, and how can the issue be managed?


Your African violets’ white stuff on the leaves is most likely powdery mildew. A fungus called powdery mildew frequently affects indoor plants including poinsettias, begonias, and African violets. Powdery mildew outbreaks on indoor plants often happen in the winter or early spring.

To prevent the fungus from spreading, pinch off and destroy any leaves that only contain a small amount of powdery mildew. Poor air circulation and high relative humidity encourage the growth of powdery mildew on indoor plants. The greatest method for preventing powdery mildew on houseplants is to modify the interior environment. By extending the distance between plants and turning on a modest fan, it is possible to increase air circulation and reduce humidity levels in the space.

Can powdery mildew be removed from a plant?

Are you curious about the white spot on your plant? The fungus illness A typical issue in gardens is powdery mildew, which affects a wide range of plants and decreases the quality and yield of fruit and flowers.

What Is Powdery Mildew?

Numerous plant species are afflicted by the fungal disease known as powdery mildew. Each of the numerous varieties of powdery mildew infects a variety of different plants. Cucurbits (pumpkins, cucumbers, melons), nightshades (tomatoes, eggplants, peppers), roses, and legumes are some of the garden plants that are frequently impacted (beans, peas).

A layer of mildew made up of several spores develops on the top of the leaves when the fungus starts to take over one of your plants. The wind then spreads these spores to other plants. If the infection is serious enough, powdery mildew can stunt the growth of your plant and lower fruit yield and quality.

How Does Powdery Mildew Spread?

Powdery mildew spores often blow into your garden with the wind, but if you’ve previously experienced outbreaks, new outbreaks could potentially result from dormant spores in surrounding weeds or old vegetative material.

Even though it needs relatively high relative humidity (i.e., humidity around the plant) to spread, powdery mildew does well in warm, dry areas (60–80F / 15–27C). It does not spread as quickly in cooler, wetter locations, and it is also hindered by temperatures above 90F. (32C). Additionally, plants in shaded places are typically more impacted than those in broad sunlight.

How to Identify Powdery Mildew

  • Plants with powdery mildew infection resemble they have been flour-dusted.
  • On leaves, stems, and even on fruit, powdery mildew normally begins as round, powdery white patches.
  • The upper portion of the leaves are typically covered in powdery mildew, although it can also develop on the undersides.
  • The most vulnerable foliage is the young foliage. The leaves dry out and turn yellow.
  • Some leaves may twist, shatter, or become deformed as a result of the fungus.
  • The majority of the leaves or other damaged parts will be covered with the white patches caused by powdery mildew.
  • The growing tips, buds, and leaves will also develop defects. Typically, these signs show up at the end of the growth season.

Small white dots on the upper half of the leaves are the earliest signs of powdery mildew. The Regents of the University of California, UC Davis, provided the image.

How to Prevent Powdery Mildew

The best method of eradicating powdery mildew, as with many other diseases and pests, is proactive prevention.

  • For your garden, pick plants that can withstand powdery mildew. Cucurbits (melons, cucumbers, squash, etc.) have many mildew-resistant varieties that are available from major seed providers.
  • Plant where there is more sunlight because powdery mildew tends to grow more frequently in shaded regions.
  • To improve air circulation around your plants and lower relative humidity, selectively prune crowded spots.
  • Spores on leaves can be removed with the use of overhead irrigation. It’s best not to rely on this as a preventive measure, though, as moist foliage can frequently lead to the development of other common diseases.

Homemade Prevention

Powdery mildew can be effectively treated using sulphur, lime-sulfur, neem oil, and potassium bicarbonate, among other organic fungicides. When given before infection or as soon as disease symptoms appear, these are most beneficial.

  • Many gardeners have demonstrated that baking soda works well to treat powdery mildew. Add 1 quart of water to 1 teaspoon of baking soda. Thoroughly mist plants because the solution only kills fungus that comes into touch with it.
  • A further efficient home treatment is milk spray. Spray roses with milk that has been diluted with water (usually 1:10) at the first indication of infection or as a preventative step.


There are several fungicides that are highly efficient with low toxicity, no residue, and long duration, especially for rose plants. Triadimefon is one case in point. It can be sprayed 1000–1200 WP of 15–% wettable powder once every 10 days for a total of 23 times. However, you should ask your neighbourhood nursery about fungicides that are legal there.

How to Control Powdery Mildew

Concentrate on preventing the illness from spreading to other plants because it is very difficult to eradicate it if plants are severely afflicted. Remove and destroy any fruit, stems, or foliage that has been contaminated. You can either burn them or dump them in the trash. Any plant that has been affected should not be composted because the illness might still be carried by the wind and linger in the composted materials.

Avoid touching healthy leaves with pruning shears after removing sick areas. Pruners should first be cleaned with rubbing alcohol.