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Lawn Disease

Lawn Fungus and Lawn Disease Guide

Lawn diseases and fungi can be discouraging. Often, it’s not clear to homeowners how the disease started, but suddenly their lawn is dying and your home’s aesthetic appeal has spiraled downward. Fortunately, most lawn diseases are easier to treat than you may think, and the bulk of lawn diseases have similar treatment protocols. In this article, we’ll take a look at the 7 most common causes of lawn disease, learn how to identify them, and how to fix the root problems. Let’s take a look.

What’s in this article?

Lawn Fungus and Disease Tips

Most of the lawn fungus and diseases you’ll run into will have similar solutions.

  1. Treat the issue as soon as possible, as most diseases will spread.
  2. Ensure you’re maintaining a healthy lawn care schedule year-round to prevent the disease from taking hold and to reduce the spread of existing disease.
  3. (Possibly) Use a fungicide treatment to eradicate the disease.
  4. Fertilize your lawn on a regular schedule in order to keep grass healthy and disease-resistant.
  5. Water deeply and infrequently, 1 to 2 times per week. This allows grass to properly absorb water and prevents fungi (which prefer moist environments) from thriving.

The 6 Most Common Lawn Diseases; How to Identify and Treat Them

Rust Disease

Type: Fungus

Rust disease is easy to spot because the grass takes on an orange-red hue that looks just like its namesake rust. Don’t be fooled though, your grass isn’t oxidizing. This is a common fungus that spreads best in moderate temperatures and is commonly seen in the spring.

How to Treat Lawn Rust

Despite this being a fungal infection of your lawn, it does NOT require a fungicide treatment or application. This fungus is pretty mild and can be treated simply with some extra lawn care over a few weeks.

  1. Be sure to fertilize the grass, as this fungus is common when the grass is undernourished and unable to fend off the spread.
  2. Mow regularly with a bag. Mowing with a bag will cut off infected grass and remove it from the lawn. Leaving infected grass clippings on your lawn can allow the fungus to simply infect the new grass.
  3. Water your grass in the mornings. If you’re watering during the day, try switching to a morning watering. Your grass will be able to absorb the water through its roots before sun exposure, preventing the fungus from sucking up water.

Red Thread

Type: Fungus

Red thread is such a common lawn fungus that many home and property owners don’t even realize it’s not normal. Watch for small, red threads popping up during periods of heavy rainfall. Red thread is not a particularly harmful fungus, and can usually be left alone without much impact on your grass.

How to Remove Red Thread

If you’re very motivated, you can apply fertilizer to your lawn to treat red thread and prevent it from coming back. However, most often red thread resolves on its own with proper lawn care.

Powdery Mildew

Type: Fungus

Powdery mildew is a mild fungus that presents with a white-ish “powdery” look. In grass, you may simply notice large patches of dead or light grass, typically in areas where the grass is having a harder time growing.

How to Treat Powdery Mildew

Powdery mildew is a tricky fungus; it can be treated with fungicide, but it is hardy and will likely return unless you improve the health of your grass. This fungus thrives when the grass is not growing sufficiently. Most commonly, this is due to:

  1. Too much shade and high nitrogen. If you’re growing grass in a particularly shady area, you may want to try a lower-nitrogen, higher-phosphorus fertilizer. This will feed your grass, and starve the fungi of the nitrogen it craves.
  2. Water infrequently and deeply. If you’re watering twice per week, try once for a longer period of time.
  3. Water in the morning. This will come up again and again when treating lawn disease. Preventing the fungi from sucking up water by watering in the early hours of the morning gives your lawn the advantage.

Snow Mold

Type: Fungus

Snow mold is a common issue in the northern states where there’s heavy snowfall. It comes in two types: Pink and Gray. Both are fungus that spreads as snow begins to melt and water sinks into the ground while the grass is still dormant. You’ll notice this as grayish-white or light pink blotches of matted grass.

How to Treat Snow Mold

Snow mold that’s already taken hold of a lawn is difficult to treat. When it comes to this fungus, an ounce of prevention is worth a pound of cure. That means you should be spreading a fungicide toward the end of fall before you get your first snow. If it’s too late, and you already see signs of snow mold, don’t worry. Rake out the matted areas as best as you can, and apply a fungicide when the snow has melted.

Summer Patch

Type: Fungus

Summer Patch is one of the most difficult lawn diseases to catch early because it resembles a simple dead patch of grass. If you’re identifying several, irregular patches of brown dead grass spreading across your lawn, it’s likely you’re dealing with Summer Patch.

How to Treat Summer Patch

In order to treat the Summer Patch, you’ll want to spread a fungicide as soon as you’re suspicious this isn’t a regular dead spot. Over the next several weeks, ensure you’re mowing at a comfortable height for your grass, watering deeply and infrequently, and raking out dead patches as soon as possible. When the patches stop spreading, reseed your grass and feed it heartily with fertilizer.

Fairy Rings

Type: Fungus

It’s probably not correct to say that we have a “favorite” lawn disease, but if we had to pick one, our favorite would be fairy rings. Fairy rings present as a curious, abnormally symmetrical circle that spreads outward from the center over time. Its name comes from days long ago when these rings inspired myths of forest fairies that would land within the rings.

This ring is actually caused by a fungus living in the soil that feeds on organic matter in your soil. It begins in one location, and the ring spreads outward as the fungus eats its way through the material.

How to Treat Fairy Rings

Fairy rings are generally considered harmless, except for the cosmetic damage they cause. They rarely do long-term damage to the lawn. On the rare occasion, a homeowner may notice mushrooms or fungus growing up within the ring. If you’d like to go the extra mile, you can rake these fungi up and fertilize your lawn, but this lawn disease is likely to simply resolve itself over time.

Dog Spots

Type: Disease

Dogs may be man’s best friend, but they’re the mortal enemy of man’s lawn. High levels of nitrogen and acidity in dog urine are a common cause of the patches on your beautiful green lawn. Fortunately, you can do something about it.

How to Treat Dog Spots on Lawn

Rinsing the area with water is a straightforward and simple solution to treating dog spots, assuming you know where a dog did its business. When you rinse the grass where a dog has peed, you’re rinsing off chemicals that would otherwise kill the blades.

Assuming you haven’t caught the culprit in action, you can still handle this with a quick evening watering, and a bit of extra fertilizer to help buffer the pH of your lawn. The extra fertilizer can help your grass integrate the additional nitrogen from dog urine, and use it to grow stronger.

Struggling with Lawn Diseases? Consider An Expert

If you’ve tried season after season to eradicate a particularly resistant fungus from your lawn, or you can’t seem to properly ID the culprit that’s killing your grass, consider talking to a local professional. Our lawn care experts offer extremely affordable solutions to treating lawn disease and often will include this service for free as part of regular lawn care maintenance services. Reach out to us today to get started solving your lawn challenges.