Powdery Mildew is a fungal disease often caused by different species of fungi particularly those belonging to the order Erysiphales.
As the name implies, these fungi leave a light or whitish powder on your plants’ foliage. While the mildew is often located on the lower leaves, it may also spread throughout the plant if the disease is left to progress.
It typically occurs in the fall and spring when there are warm days and cool nights. It can also occur in highly humid areas like greenhouses.
As a common garden disease, powdery mildew can affect almost any plant. However, certain species are more susceptible to heavy infection than others including:
- California poppy
How Does Powdery Mildew Spread
Powdery mildew spores tend to overwinter in plant debris. Once spring rolls in, it begins to produce more spores. These are then carried to your garden via wind, insects, and even splashing water from the soil onto the leaves of the plant.
It also thrives in crowded gardens where there is poor air circulation. Spores spread faster in plants that remain damp and are in close proximity to one another.
You may also like: How To Get Rid Of Earwigs
Powdery Mildew Symptoms To Watch Out For
Powdery mildew is pretty easy to spot. Some of the most common Powdery Mildew symptoms you can look for to know when your plants are infected are:
- White or gray patches on the leaves
- Mottling of leaves
- Pale-colored leaves
- Wilting and drooping of plants
While powdery mildew leaves an unattractive residue on the surface of your plants, infections are rarely fatal. But with repetitive infections, a plant can get stressed and can weaken making it less fruitful and often stunted.
It can also leech nutrients from the plant and impair photosynthesis if enough of a plant’s surface becomes covered.
Powdery Mildew Prevention
In some areas, powdery mildew infections are recurring. However, with the right garden management, you can prevent it from wreaking havoc in your garden.
If you live in an area with high humidity, if your plants are in a greenhouse, or if you have plants that are more susceptible to this disease, you might want to take these steps:
Improve air circulation by thinning out and pruning your plants
- Make sure that your plants are growing healthy. Stressed plants attract diseases much easier so correct any poor growing conditions in your garden
- Choose powdery mildew-resistant cultivars
- Avoid planting non-resistant plant varieties in the shade or in areas that might remain damp for long periods
- Spray your plants with a 40/60 ratio of milk and water every 10 to 14 days
You may also like: How To Attract Birds To Your Garden
Powdery Mildew Treatment Of Infected Plants
The easiest way to treat infected plants is by removing and discarding the infected portions. Cut back leaves that have powdery mildew on them.
Be sure not to compost them to prevent more spores from forming. Clean your hands and clippers thoroughly after removing affected parts of your plants.
Another option is to apply a fungicide to get rid of Powdery Mildew spores. You can purchase biological fungicides that contain Bacillus subtilis or Trichoderma harziannum.
You can also try synthetic fungicides that eradicate powdery mildew and protect your plants from future infections.
Of course, there are home remedies you can try to keep powdery mildew at bay.
You can mix 1/4 teaspoon baking soda with 1 quart of water. Spray affected leaves weekly as soon as you see the first signs of the fungus.
You can also use neem oil (always opt for 100% Cold Pressed Neem Oil so you don’t pay for a weaker product loaded down with unnecessary fillers) to treat existing powdery mildew and to prevent future infections.
You can also find gardening products I use in my videos here <---
You can go to my storefront using this secure link <----
If you need seeds, this is the company I use <--- and if you use code: farmer1 at checkout, you'll get 10% off your order!