How Do I Get Rid of Powdery Mildew? The Best Tips

How Do I Get Rid of Powdery Mildew
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How Do I Get Rid of Powdery Mildew

How do I get rid of powdery mildew? If you are growing succulent, you might also have asked this question. In this post, I will share my own experience and some of the tips you can use for your succulents too!

Before I answer the question, let us know what powdery mildew is. Powdery Mildew is a kind of fungal disease that thrives in different plants. It is the most common and easily recognized plant disease.

Powdery mildew is a widespread fungus on plants, trees, fruits, and vegetables. It is one of the popular and easiest plant diseases to identify, it’s symptoms are quite distinctive. It is prevalent in warm, dry weather. It does not spread so well in cooler, rainy areas. Hence, it has a chance to survive in winter seasons within the buds and tissue of the host plants.

Various plants are immune to this kind of fungal disease, however, some are more susceptible than others. The fungus develops in moderate temperature, low humid environment and overwinters in the soil. The lower leaves of the plants are the most affected, but the mildew can develop on any above-ground part of the plants.

The powdery mildew first appears as white spots and as if they dusted with flour. It can appear in stems, leaves and sometimes in fruits. The white spots can take over to leaves and to the affected area as well.

Powdery mildew may disfigure the plants’ leaves, buds, and growing tips. The plant that has powdery mildew can affect the other plant through the wind, insects and splashing water.

Powdery mildew is uncommon during the lengthened rainy season and extreme heat. As the mildew spread, the leaves become yellow and wit, eventually, the entire branch dies.

The powdery mildew is caused by high humidity. In some cases, the fungal growth can be temporarily removed by rubbing the leaves. Infections may occur when they connect to suitable hosts and especially when environmental conditions are perfect.

There are other effects of powdery mildew that are not readily visible. Fertilize to optimize the plant and also the plant health, but avoid over-fertilize with nitrogen as it enlivens young, succulent growth which is more susceptible to infection.

Powdery mildew can take away the plant’s nutrients therefore the plant can become weaker, less bloom and slow down the plant’s growth. This powdery mildew can kill the plants.

If the powdery mildew has covered the plants’ leaves, the photosynthesis depleted and the infected leaves may fall. Insufficient photosynthesis can affect the number of sugar produced.

The ideal condition for powdery mildew production is during the late spring or early summer when evenings are still cool.

Succulents that have a severe infection must be monitored closely the following spring so that if infections reoccur, they can be treated immediately.

Powdery mildew has a various genus on each plant. Many plants including succulents have powdery mildew.

However, each plant has a distinct genus of powdery mildew. It is important to start a prevention or control program before the powdery mildew occurs or at least in the earliest sign of infection.

Powdery mildews in various plants:

  • Wheat, barley and other cereals – Blumeria graminis
  • Legumes – Microsphaera diffusa
  • Grape – Erysiphe necator (or Uncinula necator)
  • Onions – Leveillula taurica
  • Apples and pears – Podosphaera leucotricha
  • Lilacs – Microsphaera syringae
  • Strawberries – Podos aphanis
  • Tree leaves – Sawadaea tulasnei
  • Oregon grape – Erysiphe berberidis
  • Arabidopis – Golovinomyces orontii

Fortunately, there are many options to prevent this fungus. Here are the steps on how to get rid powdery mildew:

  • Choose a succulent or plant that is resistant and tolerant to powdery mildew
  • Avoid watering succulents or plants from overhead to reduce humidity
  • Selectively shear the overcrowded to increase the circulation of air, this also helps to reduce humidity
  • Always sanitize the pruning tools
  • Remove the affected foliage from the plant and clean up the fallen debris on the ground
  • Spray your plants with the fungicides
  • Water the succulents every morning, so plants have a chance to dry during the day
  • Avoid susceptible succulents to humid and shady areas
  • Avoid over-fertilizing the succulents with nitrogen
  • Use healthy planting stocks
  • Avoid the chemical application to succulents as much as possible
  • Place the succulents where they can get some direct sunlight
  • Don’t over-fertilize the succulent. New growth has a tendency to prone in powdery mildew
  • Make sure soil drained properly. Insufficient can make a soil breeding ground for disease-causing organisms.

There are organic treatments to get rid of powdery mildews:

  1. Potassium bicarbonate – is an effective and safe treatment that kills spores. It has the unique advantage of eliminating powdery mildew once it’s there. It is a contact fungicide that kills the spores of powdery mildew quickly.
  2. Milk – another effective way to get rid of powdery mildew. As the milk is hit by the sun, free radicals will form that will, in turn, kill the fungus.
  3. Neem oil – is from the seeds and fruit of neem tree. It is powerful enough to kill powdery milk in less than 24 hours.
  4. Vinegar – it is very effective in killing powdery mildew because of the acetic acid in apple cider vinegar. But, be careful to not make the mixture too strong as the acidity can burn succulent leaves.
  5. Baking soda – similar to potassium bicarbonate, baking soda has a pH level of 9, enough to kill the fungus. This is the homemade organic treatment for spores of powdery mildew.
  6. Garlic – has high sulfur that can kill powdery mildews.
  7. Sulfur – it is a natural product that can control and prevent powdery mildew
  8. Copper fungicides – it is very effective when it comes to killing fungus but it is very important to follow instructions closely.
  9. Mouthwash – if this can kill bacteria in our mouth, certainly the fungal spores of powdery mildew are no match.
  10. Water – it washes off the spores before they have time to be embedded but it is only temporary. Spores may come again in plants.

5 Best Fungicide for Powdery Mildew

If the free methods discussed above did not work, you use the following fungicide for your succulents.

  1. Bayer Advanced 701270
  2. Wondercide All Purpose-Organic Insect Control
  3. Spectracide Immunex Fungus Control
  4. Wondercide Eco Treat-Powdery Mildew Killer
  5. Ferti- Lome 11380 Liquid Fungicide Spray

Here are some susceptible plants to powdery mildew:

  • Begonias
  • Sunflowers
  • Chrysanthemums
  • Dahlias
  • Roses
  • Zinnias

Here are some susceptible fruits to powdery mildew:

  • Melons                                                                            
  • Zucchini
  • Squash
  • Lettuce
  • Cucumbers
  • Potatoes
  • Parsley
  • Pumpkins
  • Grape
  • Peppers
  • Tomatoes
  • Various tree fruits

Final Thoughts on How Do I Get Rid of Powdery Mildew

There are many causes that contribute to powdery mildew. This fungus may the biggest problem for the gardeners.

Powdery mildew won’t infect humans but it can certainly kill succulents and other plants if remained untreated.

Direct sunlight helps to kill the spores of powdery mildew before they can spread to plants. As the mildew progress, the spots are getting larger and compact as large numbers of asexual spores are formed, and the mildew may spread up and down the distance of the plant.

Prevention is still the best practice. I hope that the tips shared in this post help you protect your plants from insects and pests.

To learn more about succulents, please feel free to visit my Succulent Guide page.


I am a university teacher by profession, researcher, blogger, and gardener.

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