Home Gardening

Outdoor Gardening

Organic Gardening

Modern Gardening

Urban Gardening

Gardening Business

Powdery Mildew Symptoms and Control Methods

Introduction: Hello gardeners we are back with a great information of powdery mildew symptoms and control methods. Powdering mildew is a generic term that mainly refers to a group of related fungi that are plant-specific and share common symptoms.  Because they are plant-specific, the powdery mildew that you have on ornamentals will not necessarily spread to your garden. Despite this, powdery mildew does spread simply from plant to plant and spores can easily travel through the air. They can even move through screen windows, so indoor plants are at just as much risk as your outdoor ones. What are we waiting for? Let’s get into the details of powdery mildew symptoms and control measures.

A guide to powdery mildew symptoms and control methods

One must be aware of powdery mildew symptoms and control methods for healthy plant growth. Although each type of powdery mildew is tailored to thrive on only 1 or 2 types of host plants, no type of plant is safe.  This nasty fungus attacks every kind of plant from vegetables to fruits, flowers, trees, and house plants.  Powdery mildew can just be the most common garden pest of all. Despite its pervasiveness, some garden plants are less susceptible.

Powdery mildew produces enzymes that help break up the plant cells of its host and this allows the fungi to penetrate its host plant’s cells with root-like structures. These structures can be called as hyphae, begin to create a microscopic web-like structure across the plant.  This larger web-like structure is known as mycelium.  The mycelium blocks out important light from the sun and cripples the plant’s ability to breath.

Once established, powdery mildew can spread quickly across a plant and through a garden.  The hyphae rapidly generate conidium.  This rapid reproduction means that infections can get out of hand quickly, so prevention is essential. The fungal disease powdery mildew affects a different variety of plants and takes away a plant’s nutrients. This causes all plants to bloom less and become weaker.

You should not miss the Balcony Garden Design in India.

The impact of powdery mildew on plants

Impact of Powdery Mildew.
Impact of Powdery Mildew.

Though only severe cases will be fatal to their host plant, powdery mildew is a serious problem for several plants, impeding the growth of new leaves and shoots. The disease can also if considerable portions of the plant leaves are covered in spores impede photosynthesis as the sunlight cannot reach the plant. This can be a particular problem when growing fruit or vegetable plants, as insufficient photosynthesis can decrease the number of sugars produced within the plant and affect its flavor.

Weakened Plants

Although a mild powdery mildew infection is not normally considered fatal to plants, it is an extremely tenacious fungus.  It can definitely kill plants and will hurt your harvest if not correctly treated. Powdery mildew spores simply go dormant. Many strains of powdery mildew can survive the winter on host plants, so if it is not treated accurately the infection will redevelop every spring. As the fungi penetrate host cells, they are able to extract nutrients directly from the plant.  This will cause an overall decline in plant health and vitality; and, can mainly affect the quality and quantity of flowers, fruits, and vegetables.


No gardener wants to deal with a well-established powdery mildew fungi infestation. It can seem like a relatively mild garden invader, but it can dig in deep and spread quickly. Although spores normally spread through the air, they can also be spread via animals, clothing, birds, insects, rain splatter, and through its own ever-extending mycelial network. These tiny spores can go just about anywhere without you even realizing the garden has been exposed.  It is safer to assume you are always at exposure for powdery mildew and act as if it is always in the air around you.

Powdery mildew symptoms and control

A powdery mildew fungus shows up as small, round, white or gray patches. These patches look like a fine fuzz or powder, giving it the name “powdery mildew”. These powdery patches are essentially the thread-like mycelium that pierces the plant’s leaves.

These patches will generally appear on the tops of leaves first and move their way down to the lower leaves of the plant.  As the infection progresses, the mycelium will spread across the top of the leaf area, and on to the undersides of plant leaves, down stems, and can even penetrate fruit or flowers.  This can occur quickly, and what started small can feel like it is spreading before your very eyes.  As the fungi spread, you will observe the leaves begin to yellow, wilt, and sometimes brown. Prevention is your best pest and disease management tool. For the best results, you must be treating your plants before you ever see a spot.

Powdery mildew fungi start on young leaves as raised blister-like areas that cause leaves to curl, exposing the lower leaf surface. Infected plant leaves become covered with a white to gray powdery growth, generally on the upper surface; unopened flower buds can be white with mildew and may never open. Leaves of severely infected plants turn brown and drop and the disease prefers young, succulent growth; mature leaves are usually not affected.

You may also like the Best Fertilizers for Plants.

Powdery mildew damage identification

Here we discuss how to identify powdery mildew damage in plants;

  • Several plants infected with powdery mildew look as if they have been dusted with flour.
  • Powdery mildew usually starts off as circular, powdery white spots, which can appear on plant leaves, stems, and sometimes fruit.
  • Powdery mildew generally covers the upper part of the leaves but may grow on the undersides as well.
  • Young foliage is susceptible to damage. Plant leaves turn yellow and dry out.
  • The fungus might cause some plant leaves to twist, break, or become disfigured.
  • The white color spots of powdery mildew will spread to cover most of the leaves or affected areas.
  • The leaves, buds, and growing tips will become disfigured as well and these symptoms usually appear late in the growing season.

How to Prevent powdery mildew diseases in plants

How to control powdery mildew

Remove the infected plant parts and destroy them. And remember, do not compost any infected plant, as the disease can still be spread by the wind and persist in the composted materials.

Also, spray infected plants with fungicides. Effective organic fungicides for treating powdery mildew contain sulfur, lime-sulfur, neem oil, and potassium bicarbonate.

Prevent powdery mildew

A well-planned garden will reduce the likelihood of a powdery mildew infestation;

Choosing cultivars with natural resistance to pests, disease, and keeping plants away from shady, humid areas will greatly decrease the potential for the fungi to grow.

When attempting to prevent powdery mildew, it’s best to select plants that are naturally resistant to tolerant to the fungi that cause the disease. Several cultivars of cucurbit, for example, have been developed to resist the Podosphaeraxanthii fungus and its main cause of powdery mildew.

Select plants that are resistant or tolerant to powdery mildew. Many mildew-resistant varieties of cucurbits such as melons, cucumbers, squash, etc have been developed and can be bought from major seed suppliers. Please avoid watering plants from overhead in order to reduce relative humidity. Selectively prune overcrowded areas to increase air circulation; this helps to reduce humidity around your plants.

By choosing well-drained, sunnier areas will reduce fungal growth. Avoid both overwatering and watering from directly overhead in order to decrease the relative humidity around the garden plant. Do not crowd the plants and selectively pruning overgrown areas will diminish the growth capacity as it eliminates overshadowed areas and permits better air circulation around the plant. Pruning and staking plants will improve air circulation and reduce the risk of powdery mildew.

Many gardeners want to spray their plants with a bicarbonate solution to prevent fungal growth; using one teaspoon of baking soda in one quart of water, they thoroughly spray the plants. This solution will kill fungus with which it comes into contact. Adding liquid soap or neem oil will increase the effectiveness of the solution.


Sprays are normally either preventatives or eradicants. When using sprays, coat the entire plant including the undersides of plant leaves. Applying regularly is really very important for prevention and treatment. If you are not seeing any signs of powdery mildew, apply once a week as prevention and if you are already treating an infection, thoroughly spray your plants every 3 to 4 days with the spray of your choice.


Sodium bicarbonate and potassium bicarbonate can be used as a preventative solution. However, sodium bicarbonate can have adverse effects on soil structure, and potassium bicarbonate can be damaging to plants if not diluted properly. Powdery mildew cannot survive in an environment with a pH level above 8. Though, extremely alkaline treatments can damage your plants. When combined, sodium and potassium bicarbonate can cause serious damage to plants, so they must be used sparingly. If you do choose to use bicarbonates, be sure to mix and apply carefully.

Incase if you miss the Best Manures for Vegetables.

Green Cleaner

Green Cleaner is a natural fungicide, pesticide, and insecticide.  It can be used as an eradicant and it helps dehydrate powdery mildew and coats spores to help prevent them from furthering the infection. If using a spray containing alcohol, such as Green Cleaner, only use in the evening time.  If used under direct sunlight, the combination of light and alcohol will damage your leaves, so make sure you spray your plants as the sun is going down.


Sulfur is a preventative that has been used for centuries and most effective if you use it as a foliar spray.  Sulfur must not be used in temperatures over 90°F or within two weeks of an oil spray.  It can damage ornamental plants, so be careful if using it outdoors near landscaping.

Commercial Antifungal Sprays

Serenade is a biological fungicide that acts as a preventative and it contains a bacterium that helps prevent powdery mildew infections from taking hold.  PM Wash and No Powdery Mildew can work to prevent an infection.

Oil Sprays

There are different varieties of natural oils that work well as eradicants after an infection is present. These contain jojoba oil, neem oil, or oil-containing products that are specially formulated for powdery mildew.

Powdery mildew treatment
  • Plant many resistant cultivars in sunny locations whenever possible.
  • Prune or stake plants to develop air circulation. Make sure to disinfect pruning tools (one part bleach to 4 parts water) after each cut.
  • Remove diseased foliage from the plant and then clean up fallen debris on the ground.
  • Use a thick layer of mulch or organic compost to cover the soil after you have cleaned it well. Mulch will prevent the disease spores from splashing back up onto the plant leaves.
  • Milk sprays, made with 40% milk and 60% water, are an effective home remedy for use on several plants. For best results, spray plant leaves as a preventative measure every 10 to 14 days.
  • Wash foliage irregularly to disrupt the daily spore-releasing cycle. Neem oil and PM Wash is used on a 7-day schedule, will prevent a fungal attack on plants grown indoors.
  • Water in the morning time, so plants have a chance to dry during the day. Drip irrigation system and soaker hoses will help keep the foliage dry.
  • Use a slow-release, organic fertilizer on plants and avoid excess nitrogen. Soft, leafy, new plant growth is most susceptible.

Organic treatments to get rid of powdery mildew

  • Potassium bicarbonate
  • Milk
  • Neem oil
  • Vinegar
  • Baking soda
  • Garlic
  • Sulfur
  • Copper fungicides

You may also consider the Profitable Hydroponic Crops.

Potassium Bicarbonate

Like baking soda, potassium bicarbonate will alter the pH levels of your plants, but it’s stronger and will kill powdery mildew quicker. Effective preventative treatments as well as a great choice for a curative remedy, simply mix three teaspoons of potassium bicarbonate with 3 tablespoons of vegetable oil, half a teaspoon of hand soap, and a gallon of water to make a solution that kills powdery mildew on contact.


Some gardeners swear by using a milk solution to remove powdery mildew from plants, citing the primary advantage of milk being cheap and readily available at any grocery store. With the milking process, growers mix 400 ml of milk with 600 ml of water then spray the solution onto the affected areas.

Neem oil

Neem oil is made from the seeds and fruit of the evergreen neem tree, and it is very powerful enough to kill powdery mildew in less than 24 hours. The neem oil works by disrupting the plant’s metabolism and stopping spore production. Neem oil is a great insecticide and since spores can be carried by bugs, this oil is a great preventative treatment as well.


The acetic acid in apple cider vinegar is effective in killing powdery mildew. Take care to not create the mixture too strong as the acidity of the vinegar can burn plant leaves.

Baking Soda

Baking soda has a pH level of 9, which is very high. Treating with baking soda raises the pH level on the plants and creates an alkaline environment that kills the fungus. There have been mixed reports of success when using baking soda to treat severe cases, so it could be better as a preventative treatment than a fungicide.

Compost tea

Compost tea having antifungal properties. Many organic growers, particularly in the rainy Northwest part of the country, have had great results and are advocates for the benefits of compost tea. Several companies sell equipment for making compost tea, and some growers just mix 1 part of finished compost with 6 parts of water and let it soak for a week, strain and dilute with water until it’s the color of tea.


Garlic has high sulfur content and is an effective anti-fungicide. Garlic oil can be bought commercially if you do not wish to produce the solution at home and it works best when added to organic oil mixtures.


Sulfur is a natural product that is effective at preventing and controlling powdery mildew. Sulfur can be bought as a dust or liquid and can be added to sulfur vaporizers.

Copper Fungicides

Copper is an effective fungicide, but it is very important to follow label directions closely. Too much copper will be detrimental to the plant and soil.

That’s all folks about powdery mildew symptoms and control methods in plants. You may be interested in Home Fish Farming in India.



Please enter your comment!
Please enter your name here