Lawn Care 101: How To Treat Powdery Mildew On Grass Easily

Lawns are major parts of our estate’s overall value; that’s why knowing how to treat powdery mildew on grass must be common knowledge to all owners. What waste would it be if a wide patch you planted and cared for yourself would succumb to disease?

Since they’re open areas, lawns are susceptible to all sorts of pests and infestations. Mildew is a type of mold, usually white, so if you’ve recently seen some white powdery masses in your lawn, that’s possibly mildew. 

how to treat powdery mildew on grass

As a living organism, mildew needs a particular environment to survive. Unfortunately, our outdoor patch provides just that environment, making such fungus prevalent and lasting longer.


Steps For Treating Powdery Mildew Infestation On Grass

Powdery mildew on grass comes from a specific fungus spore spreading and being catered in the grasses. If you’ve found them recently, you can take three courses of action to remove them safely: 


Method #1. Replace the grass

The first suggestion we have will be the most massive of them all: to straight out replace the grass you currently have on your lawn. Powdery mildew can be observed more commonly on a specific type of grass we’ll mention later on, and if that is the type you currently have, you can consider a replacement.

This course of action is highly recommendable if the mildew infestation, whether this powdery white or other types, has become a recurring problem in your lawn. Another reason is whether the mildew masses have completely or majorly covered your yard.

If such reasons exist, pick up your shovel and wheelbarrow and start shoveling the infected grasses off. You can replace the topmost soil layer first, then level the ground and replant a new batch of grass.


Method #2. Adjust the lawn environment

If your lawn is not yet completely covered in powdery mildew, another thing you can do is make it so the fungus causing the infection cannot survive at all on the lawn. You can do this by adjusting all the conditions in your property away from what the fungus favors.

Open up your lawn more to avoid air stagnation and increase its circulation. Open lawns will also lower their capability to trap water vapors in the area, which pulls the favor away from the fungus.

Trimming some surrounding tree branches and bushes will also let more sunlight into the lawn surface, which is favorable to grass growth and at the same time preventive of the fungal infection.


Method #3. Apply chemical treatment

The last thing is for a more reliable and longer-lasting solution is to pick a suitable fungicide depending on which mildew can be found in your area and apply it. These pose a bit of safety and health concerns for you and your neighbors if you’re inexperienced, though.

For this course, get your neighborhood’s approval first, especially if you’re working in a large area and several homes are in the vicinity. You might as well get a professional’s opinion first.

These three ways can be taken one after the other on the same lawn for maximum mildew removal. If you have further mold problems outdoors, here’s an interesting article on how to get rid of mold in the yard that you peruse further.


What causes powdery mildew in the grass?

Beyond dealing with them, you need to understand what exactly causes the powdery mildew in your lawn and what variables are allowing it to proliferate.

First, let’s talk about the cause. Powdery mildew is produced by a fungus called Erysiphe graminis, a type of fungi that survives by attaching itself to a living host, which is the grass.

Though it requires a particular setup to survive, this type of fungus is quite persistent as they can survive and wait out until such conditions exist. They do that by having their spores lie dormant until it’s blown somewhere favorable enough.

The moment they land somewhere conducive, these fungi grow and produce asexual spores that masses up into the powdery mildew you see on your lawn. While this fungus commonly only adheres and reproduces on the outer surface of the leaves, they can start an infection at only 2 hours from spore contact.

For the environmental condition, this fungus prefers certain grasses, particularly turfgrasses. Knowing about such plants will let you correctly pick something for the grass replacement if you choose that course of action.

Other than the type of grass, powdery mildew can appear when there’s reduced air circulation or extraordinarily high relative humidity or water vapor in the air. It can also happen due to low light intensity and favorable air temperatures, in about 60-70 degrees Fahrenheit.

Since this fungus can lie dormant to survive, it won’t just naturally go away, so we recommend you deal with it as soon as you can. On that note, you might as well check our article on “should you get mold inspection when buying a house”.



There’s just so much to learn about caring about your lawn, and knowing how to treat powdery mildew on grass is just a tiny bit of it. It is quite an important task, though, so you make sure you follow our suggestions well and keep that lawn blooming.

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