Different lawn diseases attack different lawn types and it is important to take care of your turf to prevent them and at the same time keep an eye out for any possible signs of common lawn diseases. The sooner you treat your lawn, the better.

Typically, lawn diseases have their seasons, however, winter and summer are prime times for many diseases. Lawn diseases start to develop earlier than winter or summertime, but the first signs start to show as the temperatures go low or warm-up.

It is vital to know that damage in your lawn doesn’t always mean it is one of the common lawn diseases. You need to make sure a professional lawn care company take a look at your lawn to diagnose it. Don’t start treatment on your own without being absolutely certain. You could do more damage to your turf if treating badly and improperly.

common lawn diseases list

5 Common Lawn Diseases to Watch Out For

Here are some of the most common lawn diseases and how to best identify them.

Brown Patch

Brown patch is a common lawn disease and grasses that are typically affected are perennial ryegrass, tall fescue, Kentucky bluegrass, bentgrasses, and St. Augustinegrass.

Brown patch affects lawns during humid and hot summer months. It shows up as roughly circular, large, irregular patch that appears to be dry or already dead.

If the disease has been active for some time now, the inside of the patch may recover, leaving thin grass or a ring of dead grass around it.

With St. Augustinegrass, this lawn disease can look a bit brownish with a yellow ring.

Red Thread

Another common lawn disease. Red thread appears as yellow or light-green patches, but if you come closer, you will notice orange-yellow spores on the grass blades. Grasses that are usually affected by this disease are perennial ryegrass, zoysia, and Kentucky bluegrass.

You will most likely notice red thread during the summer months or early fall, especially in areas with poor or no ventilation. In some cases, rust may appear in the spring, for example, if your lawn hasn’t been fertilized for some time now. You need to feed your lawn throughout the year so you could prevent it from red thread and other lawn diseases.

Snow Mold

There are two types of snow mold – gray snow mold and pink snow mold and grasses that are mostly affected are creeping bentgrass and ryegrass.

Snow mold grows under snow cover, however, pink snow mold can also show up during wet and cool weather, where there is no snow. It shows up as whitish-pink or grayish-white patches of matted grass and is easily noticeable in spring when the snow starts to melt.

Powdery Mildew

Powdery mildew is a common fungal lawn disease. It is most common on cool-season grasses such as Kentucky bluegrass. It can appear quickly, mainly in areas with poor ventilation during overcast and cloudy periods.

You can easily identify powdery mildew by its white dust appearances.


Is your lawn looking a bit rusty? It is not the same rust you see in the kitchen or in an old car. Rust is a lawn disease caused by a fungus, an organism that can infect your turf and give it the look of rusted metal.

If you suspect your lawn has a rust fungus disease, look for yellow and small flecks on the blades. This way you will be certain it is rust.

As this disease grows, the yellow spots will enlarge and release orange spores. This lawn disease prefers warm temperature and humid weather. Low nitrogen levels can also be a causing factor.

Fungicide application can be used as a prevention to prevent future growth.

causes lawn diseases

What Causes These Lawn Diseases?

It can be frustrating to see spots ruining your beautiful green yard, especially if you are not sure how they got there or what to do to get rid of them. Below are the common causes of brown patch, red thread, snow mold, powdery mildew, and rust.

  • Brown Patch: Due to fungal problems, brown spots show up as small, irregular patches. Extremely humid or rainy weather can stimulate fungal outbreaks, as well as, poor air circulation and a lack of sunlight. Even though you can’t control the temperature and the weather, you can apply a preventative fungicide application to treat active disease and prevent future problems. Grubs may be another cause for brown patch. Patches caused by grubs will roll up when rakes and feel sponge-like because grubs damage turf by eating the roots and roots are practically destroyed. To repair brown spots, you need to remove the dead grass and apply the proper product.
  • Red Thread: Almost any type of lawn is susceptible to this common disease. But it is not uncommon for some turfs to have more issues than others due to maintenance, soil conditions, etc. The causes of red thread can be understood by considered three factors, the pathogen (the disease), the host, and the environment. The hosts are plants that are lacking in nitrogen and usually experiencing slower growth than before. The pathogen or disease itself is present in the layer of a lawn and it cannot be completely removed. When the grass plant is weak, the weather is humid, and the temperature is favorable for fungal growth, red thread will appear and if done nothing, it will continue to grow.
  • Snow Mold: Melting snow or a blanket of snow may look beautiful until you see the damage it can do to your green lawn. This lawn disease is problematic when there is deep and heavy snowfall in your area. All that weight and pressure on grass plants together with wintertime moisture and lawn debris can cause trouble or also known as snow mold. It is not possible to face snow mold every season. It is pronounced in springs when the snows months were early but heavy enough to cover your lawn before the ground is fully frozen. The warm ground will stimulate fungal growth and you’ll face the consequences when the spring comes.
  • Powdery Mildew: A fungal disease found throughout the country. It is caused by fungal species with a limited host range. High humidity combined with low soil moisture favors powdery mildew. The main symptoms usually appear in the growing season on grass plants. Powdery mildew can be seen on young leaves. Infected leaves are covered with gray or white powdery growth while unopened flower buds are white and may never open. The leaves that are seriously infected turn brown and die. This disease prefers succulent and young growth white more mature leaves are not affected.
  • Rust: Rust lawn diseases are most likely to show from spring through fall during wet weather. Also, it can appear during dry periods and high temperatures. Undernourished and stresses turf is susceptible to rust. When inspecting your lawn, check for light-yellow and irregular patches and small flecks on grass blades. One good thing is that rust doesn’t harm pets or children. When a rust disease progresses, you may notice thinning turf. Pay attention to areas that have compacted soil, are shaded, and are newly seeded. The spread, as well as, the development of fungi is made even worse in areas where there is excessive wetness, less grass, or not enough nutrients required for growth and greening.

How to Treat and Get Rid of Lawn Diseases

Many conditions can cause lawn diseases and dead grass on your beautiful, green yard. Luckily, there are some effective treatments and ways to get rid of brown patch, red thread, snow mold, powdery mildew, and rust.

how to treat lawn diseases

Learn How to Prevent and Treat Brown Patch

Brown patch can be prevented before the symptoms arise, however, most lawn owners decide to avoid preventative maintenance due to the time and costs involved in the treatments. Here is a list of preventative measures you can apply to help strengthen your soil against brown patch.

  • Use the right amounts of nitrogenous fertilizer.
  • Regular watering set for the early morning instead of in the evening.
  • Proper mowing to stimulate air movement between leaves.
  • Overseeding using the right fescue varieties that are most effective in disease resistance.

Treating brown patch lawn disease requires the application of a fungicide. The fungicides that are available at retail stores are not so effective. An expert lawn care provider has access to products and treatments are much more effective, Our experts are trained to recognize brown patch and are actively treating it, along with other turfgrass diseases.

Control, Treat, and Fight Red Thread

Lawn owners wonder what can be done to fight red thread when it shows up year after year. The key is to disrupt the disease so that the fungus can’t grow further. Although it is not possible to control the weather or remove the disease, the best way to manage red thread is to find the host plant and make it stronger using fertilizer.

The primary treatment for red thread is to fertilize your lawn. You need to use the proper amount of nitrogen, of course. Nitrogen applied in the early fall will feed the turf in the spring. Keep in mind that much of that nitrogen will be gone by early summer. It is effective to apply 0.2 pounds of nitrogen per 1000 square feet of lawn.

Treating red thread with pesticides and chemicals is not necessary and also not recommended for residential lawns. Chemicals are only an option for extreme cases.

Get Rid Of Snow Mold Safely

The remedy to beating snow mold lawn disease is prevention. There are no fungicide treatments or chemicals that work on this type of lawn disease. If you have repeated snow mold issues in the spring, you can use a preventative application of fungicide in fall, before the first  snowfall.

If you don’t use a preventative fungicide and you notice snow mold damage in the spring, you will need to rake the areas that are already affected to loosen matted grass. This tactic will help your lawn dry and give your grass room to flourish and grow.

Here are some preventative tips to keep in mind:

  • Always mow before the first snowfall. Long grass is a welcoming ground for snow mold. Mow 1 or ½ inches shorter than you usually do.
  • Don’t let the leaves to pile up because a layer of leaves creates a convenient environment for snow mold.
  • Be careful with nitrogen. Although a fertilizer containing nitrogen is great for greening, too much of it can invite snow mold. Experts recommend applying a slow-release fall lawn food.
  • Use a preventative fungicide. The appearance of snow mold lawn disease is dependent on the temperature and the weather, however, if it becomes an annual issue, you can apply fungicide in the fall, after your last mowing and before the first snowfall.

Organic Ways to Kill Powdery Mildew

For those of you who don’t want to use chemicals to get rid of powdery mildew, here are a few organic treatments to consider.

  • Milk: Lots of studies have shown milk is even more effective at destroying powdery mildew than chemical applicants. Although experts aren’t sure why milk is so effective, they believe that when milk interacts with the sun, it produces radicals that are toxic and kill fungus. You can mix water and milk (60/40) and spray onto the plants. For a strong effect, you can use whole milk.
  • Garlic: Garlic is an effective fungus killer, thanks to its high sulfur content. Garlic oil can be purchased in any store and it works best when added to oil mixtures. You can crush six garlic’s cloves and add to 1-ounce organic oil and 1-ounce rubbing alcohol. Let set for one-two days. Soak the garlic and strain out the crushed garlic. Add the alcohol and oil mixture and garlic water to 1 gallon of water. Spray the affected plains.
  • Copper Fungicides: Copper is an effective fungicide, however, it is important to follow directions precisely. Too much copper and you will destroy both the plants and the soil.

Non-Chemical and Chemical Ways to Treat Rust

Lawn rust can be treated without using fungicides or chemicals. Fertilizing your lawn is the best way to treat this problem. Regular fertilization and using an appropriate spreader will stimulate the grass to grow faster.

Watering your lawn early in the morning gives it time to dry out which can discourage lawn rust growth.

Using chemicals to kill rust in your lawn is not necessary. It is only recommended to use this method when non-chemicals practices are not effective.

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We Can Help You Treat These Common Lawn Diseases

Your lawn needs care and different nutrients depending on the season, weather, and temperature. Our lawn care experts can provide you with a lawn program that suits your needs.

We will take care of your weed control, lawn fertilization, aeration, seeding so that your lawn will always be green and healthy all year long.

You can depend on our professional lawn care services. Give us a call or schedule an appointment here.