Powdery Mildew: Treatment and Prevention
It’s difficult to grow your own vegetables and herbs, but I get frustrated when I have to combat powdery mildew.
One of the most common diseases to affect your plants is itchy rot, particularly if you’ve been gardening a long time. You may notice white, powdery spots on the stems and leaves of your plants. It is caused by many different types of fungus.
When left unchecked, it can drastically reduce your plants’ vegetative growth and inhibit their ability to produce fruit or flowers.
Powdery mildew can be treated in several ways, which I will cover below.
What is Powdery Mildew?
Regardless of the particular kind of fungus that afflicts your plants, all of them act in the same manner; they spread over your plants’ foliage and prevent photosynthesis and nutrients from being absorbed. Without catching it early, the damage may be too far along to stop, and you will have to remove the plant from your garden completely.
How To Identify Powdery Mildew
It manifests itself by covering a plant’s leaves with a distinctive powdery white dust. At first only a small amount of dust is visible, but it becomes larger as the disease progresses.
The difference between downy mildew and powdery mildew:
The appearance of powdery mildew can be confused with downy mildew. Downy mildew is only found on the underside of plant leaves, while powdery mildew can appear anywhere on the plant. Downy mildew also lacks the powdery appearance.
Symptoms of Powdery Mildew
Once the disease has advanced, the white spots begin to form a root-like structure inside the leaves, preventing nutrition from reaching the leaves. The leaves become starved and turn yellow.
The disease can progress to the point that leaves turn brown and die. Dying leaves open the plant up to sun damage, malformations of buds and fruit, and possibly failure to fruit altogether.
How To Prevent and Treat Powdery Mildew
There is no complete solution for preventing powdery mildew outbreaks because spores are carried through the air on wind gusts. If the conditions are right, then the spores fall on the plant surface, where they multiply if moist enough. In damp conditions, powdery mildew is not a problem. However, other types of plant diseases may grow.
Here are some ways to prevent powdery mildew:
- Powdery mildew-resistant plants should be chosen.
- Shade is not a good place to plant vulnerable varieties.
- Make sure you manage aphid infestations, as they can carry the spores into your garden.
- Keep leaves moist on a regular basis.
- When you see dried or diseased plant matter, remove it immediately.
When your plants have a serious mildew problem, you can use a variety of home or professional treatments.
Best Products to Treat Powdery Mildew
The mildew can be cured with a variety of commercially available products, including copper-based fungicides (fungicides that kill the spores of powdery mildew).
However, there are other treatments that can provide good results at a lower cost. These include:
Baking soda, which you keep in the kitchen for cooking is also useful in preventing powdery mildew in your garden. Simply dilute one tablespoon of baking soda in a gallon of water.
To help the solution adhere to the leaves of the plants, add 1/3 teaspoon dishwashing liquid. Do not save leftover solution. Make a new solution each time you treat the plants.
Potassium bicarbonate is a powdery compound used in many applications including food processing, medicinal products, wine-making, and the treatment of powdery mildew on garden plants.
It is far more effective to use potassium bicarbonate against powdery mildew that already exists, rather than as a preventative measure.
Powdery mildew in your garden can be treated with mouthwash that you keep at your home or in the medicine cabinet. The mouthwash should be ethanol-based, and it should be diluted with three parts water.
Its antibacterial properties allow it to be used as an anti-mold spray to eliminate spores that would otherwise continue to reproduce and damage your plants.
Dilute vinegar with water and use as a powder mildew treatment by mixing four tablespoons in one gallon of water. Spray it on plants and allow it to sit for three days, even if they contain edible fruits and vegetables.
Despite this, vinegar is an acidic substance that can damage your plants if used frequently.
Many years ago, sulfur and sulfur spray were used to prevent and eliminate mold. Sulfur spray can be found at your local garden center or plant nursery. It can be used to treat powdery mildew and many other plant diseases.
The combination of sulfur and lime is thought to be even more effective in killing powdery mildew, but these compounds can burn fragile plant tissue, so by applying them correctly and spacing them apart, users avoid harming their plants.
The use of milk for powdery mildew has been recommended for generations, however its science is only now being investigated.
A study found that 10% milk was as effective as other treatments for powdery mildew. Milk is an inexpensive and organic way to target this disease and can be applied safely in any planting area. Powder mildew spores need a warm, dry environment to thrive. Powdery mildew spores cannot multiply in moist conditions, so keeping your garden plants slightly damp will help prevent their spread. **Note: Other diseases thrive in damp conditions, so making your garden plants damp won’t work in the long run.
Neem oil comes from the fruits and seeds of the neem tree, which originates in India. It has been used for thousands of years as an insecticide and anti-fungal, and today it is known as an organic compound that eliminates insects in gardens.
In addition to controlling insect pests, neem oil prevents powdery mildew from spreading. It is generally recommended as a garden spray to kill pests, but can be used for powdery mildew as well.
It may be more efficient to use it as a preventative than a cure if the problem has already occurred. While powdery mildew can be a difficult to eradicate plant disease, good gardening practices can reduce the risk of this problem.
The best way to determine which of the above treatments will work for your garden is to test them out.