Don’t Leave it A-Lawn: Common Lawn Diseases Lurking in Your Yard

It doesn’t matter if you have the best lawn on your yard, if it’s made with natural grass, it isn’t immune to disease. There are a lot of lawn diseases that have increased occurrences during Spring and Fall. Here we feature information on cool weather diseases, how they start, and how you can easily treat them. 


All grass types are vulnerable to lawn disease, with the amount of damage highly dependent on how you maintain your lawn. And as with any disease, before any cure or treatment is given, the root cause must first be identified to improve the chances of fighting it.


What causes lawn disease?

The main cause of lawn disease is microscopic living organisms. These include fungi, nematodes, phytoplasmas, bacteria, and more. However, for most lawn diseases, the culprit is usually pathogenic fungi.


Pathogenic fungi remain dormant in the soil until environmental conditions are favorable. A simple infection can easily turn into an outbreak that can be distributed by wind, foot traffic, rain, or more. Since these organisms have no stems or roots, they get their nutrients solely from their host, or the grass blades making up your lawn.


How does lawn disease start?

There are 3 major conditions that must be met before lawn disease develops. These conditions include:


  1. Presence of pathogen in and around your soil.

  2. Type of grass susceptible to that specific pathogen.

  3. Favorable environmental conditions.


The third and last one has the most impact on the vulnerability of your lawn because it’s almost certain that there are pathogens in your soil, and your lawn will always be susceptible to a specific type of pathogen. However, having just the perfect conditions necessary before the pathogens begin to flourish doesn’t happen every day. Proper maintenance and meticulous inspection is your best bet in discouraging any unwanted growth.


For your reference, we highlight 5 of the most common lawn diseases below:


1. Brown Patch (Rhizoctonia Solani)

Brown Patch | Common Lawn Diseases


This is one of the most widely spread diseases that affect almost any cool-season turf lawn. This specific disease can wreak havoc on Tall Fescue, Kentucky Bluegrass, and Perennial Ryegrass especially when nighttime temperatures start dropping. Although easy to identify, it is known for being notoriously sneaky that by the moment you notice it on your turf, it would already be at significantly high levels. Fortunately, this disease responds well to various fungicide brands.


2. Large Patch (Rhizoctonia Solani)

Large Patch | Common Lawn Diseases


True to its name, the large patch begins as small baseball-sized patches that eventually develop into automobile-sized areas. With an active infection, the edges of the turf display an off-color shade with a healthy patch of green in the center. Fungicide control is best attained with applications from the previous Spring or Fall upon first sight of the disease.


3. Summer Patch (Magnaporthe Poae) or Necrotic Ring Spot (Ophiosphaerella Korrae)

Summer Patch | Common Lawn Diseases


Though not as prolific as other diseases, the summer patch and necrotic ring spot in Kentucky Bluegrass may be one of the more difficult lawn diseases to manage. Symptoms usually come up as tan or brownish circular patches on the turf during late summer.


Once the symptoms appear, options for control will be limited. Frequent irrigation may help the turf recover but at this point, chemical options are ineffective. The best management for this form of disease is prevention in the form of fungicides.


4. Pink Snow Mold (Microdochium Nivale)

Pink Snow Mold | Common Lawn Diseases


The name of this disease suggests that this mold would be easy to identify due to the pink color. However, pink snow mold is only pink for a short, limited time and does not even need snow to infect your turf. In cool areas with humid weather, pink snow mold can occur any time of the year.


Symptoms show small circular patches that may have a water-soaked appearance along the edges. Under wet conditions, white mycelium may appear in the patch with the margins looking reddish pink. Under dry conditions, the same patches may become tan and look bleached. There are options to control pink snow mold once the symptoms show, but preventive applications are still much more effective at keeping the disease away.


5. Pythium Blight (Pythium Aphanidermatum)

Pythium Blight | Common Lawn Diseases


Pythium blight is a foliar (relating to leaves) disease that occurs swiftly in vulnerable stands of turf just like in seedlings. Technically classified as water mold, these outbreaks are commonly associated with poorly draining soil or damp and humid conditions where the turf leaves experience very little drying.


Newly seeded areas receiving daily watering can provide favorable environments for pythium development. Symptoms include circular areas up to 3 inches in diameter and grayish foliage with a water-soaked appearance. White mycelium may also be present. Use of preventive fungicide is possible but once symptoms appear, chemical interventions are not nearly as effective in treating the disease.


How do you discourage the growth of lawn disease?

  1. Do not over-fertilize the grass.

  2. Do not starve the grass; simply adhere to a balanced fertility program.

  3. For warm-season grass, fertilize only after breaking dormancy. Never fertilize in the Fall since the disease can return when the weather gets cooler.

  4. Do not irrigate unless necessary. Water in the early hours of the morning while the grass is still covered in dew. Watering right after the dew has dried extends the amount of time the soil and grass is wet.

  5. Sugar is secreted to the grass surface and mixes with morning dew. This same sugar becomes a food source for leaf spot and other pathogenic fungi. Drag a hose over the grass to remove the sugary dew mix.

  6. During an active infection, avoid the use of herbicides. If there is an urgent need for damage control, turn to spot spraying instead. Avoid herbicides that are known to further encourage leaf spot and other lawn diseases.

  7. Skip the fungicide if the disease doesn’t progress way past the leaf spot stage.

  8. Once any disease reaches the crown, the grass affected will inevitably die. Instances like these where the use of fungicide is warranted, apply as needed the soonest possible.



The answer’s pretty straightforward--avoid natural grass. You might be thinking, “but what’s a lawn without my grass?!” and you know what, we perfectly understand that reaction. Know what else we understand and firmly believe? That you deserve only the best. So why don’t you go for a much better option; one that is more eco-friendly, not a time-waster, and stays aesthetically pleasing for way longer than natural grass.


Yes, we’re talking about synthetic grass.


Unknown to many, fake grass is actually a more nature-friendly choice compared to real grass. Designed to last for years, synthetic grass minimizes carbon footprint, water usage, and removes the need for fertilizers, fungicides, and herbicides.


Artificial grass will never ever catch a disease, eliminating any possibility that you have to use harsh chemicals for treatment or worse--seasonal preventive application.


If you’ve read up to here, chances are you’re really interested and possibly just really tired of having to go through all the stress involved in battling lawn disease. If you need more resources on synthetic grass and why you should make the switch today, we recommend you read more here.


Fake grass may look like a villain at first glance but what the uninformed ones consider a gray area, is actually the greenest choice you can possibly make. It’s never too late to make the switch, take the more mindful option and never be bothered by lawn disease ever again.