10 Common Lawn Diseases and How to Treat Them

Learn about 10 common lawn diseases and how to treat them in this informative blog post. Get expert tips and advice to keep your lawn healthy and beautiful.

Introduction to Lawn Diseases

Do you take pride in having a beautiful lawn outside your home? But are there patches of grass that suddenly turn brown or yellow, or areas where the grass is thinning out? If yes, then it could be because of a lawn disease.

A disease on your lawn can be frustrating and unattractive. Besides, it can weaken the plants, making them more vulnerable to other problems like insect infestations.

In this blog post, we’ll take a closer look at common lawn diseases and how to treat them. However, before diving into the treatment aspect, let’s understand what exactly are these diseases.

What are Lawn Diseases?

Lawn diseases refer to any fungal or bacterial infections that affect the health of your turfgrass plants. These microorganisms thrive on moisture and warm weather conditions and tend to spread through unhealthy practices or unfavorable weather.

There are several species of fungi and bacteria that thrive in humid climates during periods of extended rain, humidity with high temperatures. Fungi spores typically exist within soil particles but also travel via wind and human activity. Some common types of fungi that cause lawn diseases include Rhizoctonia (brown patch), Pythium blight (Pythium aphanidermatum), fungus (Dollar spot), Microdochium nivale (pink snow mold), etc.

Each type has its unique symptoms but typically share some similar ones like:

  • Brown spots
  • Discolored areas
  • Rings
  • Patches where grass is thinning out
  • Mushrooms or unusual growths on lawns.

If you’re unsure what’s causing damage to your lawn, I suggest contacting your local horticulturalist, gardener or arborists for confirmation.

Why Are Lawn Diseases a Problem?

Lawn disease often begins with less visible symptoms like small white powdery flakes on leaf blades; however if left untreated over time gets more severe. For instance, fungi thrive off moisture and spread through close proximity to the affected garden area.

Additionally, fungal growth depletes nutrients from the soil and plant tissue often leads to yellowing leaves or brown spots and reduced growth rate in plants. Lawn diseases not only impact the beauty of your lawn, but they can also significantly damage or kill entire parts of it.

To better understand you lawns health ensure practicing proper lawn care. This includes mowing grass at correct height for lawn variety; water your yard deep once a week vs frequently overly saturated areas; remove thatch that chokes plant roots, over fertilizing land can cause extra stress points leading to disease and other issues overtime. Remember prevention is always key maintaining a healthy green turf!

Now that we have brief insight lawn diseases lets explore into 10 Common Lawn Diseases homeowners face as well as treatment methods commonly used by landscape professionals around the country.


What is Pythium root rot?

Pythium root rot is a destructive plant disease caused by the fungus-like organism Pythium that attacks and damages the roots of various crops, leading to reduced growth and yield. [Wikipedia]

Types of Common Lawn Diseases

Maintaining a beautiful lawn can be challenging, especially if your grass is susceptible to various diseases. Understanding the different types of common lawn diseases and the symptoms they produce is essential to keep your lawn healthy and lush.

Fungal Lawn Diseases

Fungal diseases are the most prevalent type of lawn disease. They can develop at any time of the year but tend to thrive in warm, humid weather conditions. Here are three fungal lawn diseases that you should be aware of:

Red Thread

Red thread disease creates patches of pink or red fungus on the grass blades, causing them to die and appear raggedy. You may also see small white or pink threads coming from infected areas. Your grass might become discoloured with circular dead spots.

To control red thread disease:

  • Water your lawn early in the morning.
  • Improve soil drainage.
  • Fertilize your grass regularly with nitrogen-rich fertilizer.
  • Mow your lawn high every two weeks.
Brown Patch

Brown patch disease occurs when large circular brown patches appear in a healthy green turf area during hot and humid weather conditions. It affects all lawns but thrives notably well in bluegrass and fescue lawns.

To eliminate brown patch disease:

  • Ensure that you water correctly by watering early in the morning.
  • Reduce excess shade-causing tree branches around affected areas.
  • Fertilize less frequently with phosphorus-rich fertilizers during spring (Mid-March through April) when conditions favour fungal growth.
Powdery Mildew

Powdery mildew disease grows as thin white powdery substances on blades of grasses, primarily caused by dense foliage which prevents air circulation due to poor light transmission with growth mostly occurring amid autumn’s cooler temperatures from September through October.

Control measures against powdery mildew include:

  • Watering plants and grass in the early morning hours.
  • Fertilizing before early spring, usual lawn maintenance, and cultural practices.

Bacterial Lawn Diseases

Bacterial infections have symptoms very similar to those caused by fungal infections. However, they develop more slowly than fungal diseases. Here are some common bacterial lawn diseases:

Fire Blight

Fire blight disease typically affects fruit trees, but it can also infect shade trees and ornamental plants. Lawns might get infected with fire blight as well. The most common symptom of this disease is wilting branches having dark brown or black discolouration.

To control fire blight disease:

  • Ensure proper watering techniques throughout the year.
  • Always sterilize your pruning tools after each trimming session on an infected plant or tree.
  • Promote airflow through means of thinning shrubs or hedges with moderate fertilization.
Crown Gall

Crown gall is a bacterial infection that causes tumors or growths on the crown (bottom part) of stems, roots, and leafy bases in turfgrass. Younger plants are usually more susceptible to the infection since their bark is thin rather than thick like mature ones.

Control measures against crown gall disease are:

  • Prevention: Only purchase seedlings from reputable certified nurseries.
  • If your yard already has it, remove the infected plants immediately without disturbing their root system.
  • Grow resistant varieties of crops and crop rotations to rid soilborne pathogens.

Viral Lawn Diseases

Viral diseases hardly affect lawns, but when they occur impacting how much you must keep an eye out for them because there are no chemical treatments available once contracted mostly transmitted by vectors such as insects causing fungus-like damages.

Here are two viral lawn diseases you should be aware of:

Yellow Patch

Yellow patch appears as small circular patches with yellowish tint outlines surrounding large irregular dead spots in lawns particularly during the autumn and winter months.

Control measures:

  • Ensure well-draining soil and maintenance of an appropriate balance of water levels in plants.
  • Avoid excessive shade.
Necrotic Ring Spot

Necrotic ring spot is a viral infection that causes rings or crescents around lower grass tips, causing blades to die. This disease occurs when the soil faces damp conditions with moderate elevated temperatures present. Symptom appearance happens around May-August.

Control measures against necrotic ring spot are:

  • Closely monitor nutrient management strategies which aim at balanced seasonal rates of nitrogen fertilization
  • Aerification: Open up spaces in soils
  • Reduce your watering habits to prevent excess moisture accumulation levels.

Symptoms of Lawn Diseases

A healthy, well-maintained lawn is a beautiful sight. It’s lush green color and soft texture offers great appeal to the eye. But when disease strikes, it can turn into a nightmare to deal with. That’s why it’s crucial for homeowners to learn how to identify signs of lawn diseases in their yards.

Here are some common symptoms of lawn diseases:


One telltale sign that your lawn might have a disease is discoloration. The grass may take on shades of yellow, brown, and gray instead of the vibrant green you’re used to seeing. Pay particular attention to any spots within the yard where the grass appears unhealthy or different from others.

Thinning Grass

Another symptom that something could be wrong with your lawn is thinning grass. When there are dead patches visible scattered around the yard or areas where the blades look weakened, you might need to investigate further.


Mushrooms growing in your yard may seem like no big deal since they appear neat looking but they can indicate underlying fungal issues within lawns. When mushrooms or fungi invade, they usually signal one thing: soil moistness beyond acceptable limits which increases incidence and severity of infections.

Easily Uprooted Turf

If turf uproots easily and doesn’t have good grip in certain areas when pulled, this is another clear sign that something could be wrong with the health of your lawn. Healthy grass roots run deep into soil unlike infected roots that weaken quickly due too often underground penetration by fungal threads robbing them off strength making them easy left uprooted from shallow dips.

Strange Patches appearing

When patches start appearing on an otherwise even surface due without any external factors (for instance oil spills), it calls for attention as these could be early stages of diseases creeping into those spots leading other sections towards infection too unless treated properly right away before spreading.

Increased Insects and Pests

When an area of the lawn looks unhealthy or infected, it naturally attracts insects and other pests that can destroy lawns in various ways. You may see increased pest activity around specific areas of your yard if a disease is present there.

Powdery Growth

Powder growth primarily seen on grass blades or even stem basically resembles tan to white powder similar to talcum powder. It usually indicates fungal issues that can spread fast when not addressed right away.

Excessive Weeds

Weeds are hardier than ordinary turf grasses and, unfortunately, they thrive in unhealthy environments. If you notice weed growth getting out of hand or spreading quickly in certain areas of your yard, it’s possible that disease could be the root problem behind it.

Discoloration at Leaf Tips

When individual grass blades have discolored tips (often appearing yellowish), think back carefully about the kinds utilities which were used to service that region as these would have contributed to soil infection leading conditions like fungal spores surviving within over longer timespans until given a chance to propagate.

Lesions on Leaves

Lesions appear usually as brown spots randomly scattered all through the blade seemingly obvious when inspecting each closely where edges often curl upwards with marginally visible concentric rings growing towards base which bursts through further accumulation bacterial pathogens munching up away healthy leaves in patches.

These symptoms might seem alarming for maintaining a good-looking garden space but identifying diseases early on would help minimize damage and save resources concerning inconveniences like clearing entire fields off time-consuming fungal wastes just because diseases weren’t identified soon enough making it an important step for many homeowners.

Ways to Prevent Lawn Diseases

Maintaining Proper Lawn Care Practices

One of the best ways to prevent lawn diseases is by maintaining proper lawn care practices. By taking care of your lawn, you can help keep it healthy and strong, which will make it less susceptible to diseases and other problems. Here are some essential practices to follow:


Proper mowing is key to maintaining a healthy lawn and preventing diseases. Make sure your mower blades are sharp so that they cut cleanly through the grass rather than tearing it. Torn grass is more vulnerable to disease. Additionally, you should never remove more than one-third of the grass blade at a time, as cutting too much at once can weaken the grass and make it more likely to be infected.


When it comes to watering your lawn, remember that less is often more. Overwatering can cause shallow root growth, which can make your lawn more prone to disease, pests, and stress during periods of hot weather or drought. Instead, aim for infrequent but deep watering sessions that allow water to reach down into the soil.


A well-fed lawn is a healthy lawn, but be careful not to overdo it when fertilizing. Too much fertilizer can cause excessive growth that strains the lawn’s resources and makes it more vulnerable to disease. Choose a balanced fertilizer that provides essential nutrients without overwhelming your turfgrass.

Keeping Your Lawn Disease-Free

In addition to proper maintenance techniques like mowing, watering, and fertilizing correctly, there are other steps you can take to prevent lawn diseases from taking hold in your yard.

Reseeding Bare Spots

Bare spots in your lawn may seem like small things compared with full patches of lush grass but patchy areas can attract pests such as insects causing havoc on healthy portions of the garden while simultaneously blocking new shoots from growing resulting in disease susceptibility.Re-seeding these areas could be one prevention method to trying to fill up the bald patches, re-establish the thick grass and reduce opportunities for disease development.


Aeration involves removing small plugs of soil from your lawn to allow nutrients, water, and air into the root zone. It can help strengthen turfgrass roots reducing their vulnerability to challenge from diseases and pests. This technique can make sure that essentials have quick access to your plants hence promoting healthy growth in your garden.

Soil Testing

We know the importance of fertilizing a lawn every season but it is difficult to know what nutrients our soil lacks or has in excess. Getting an accurate assessment of essential nutrients available or unavailable can help us figure out which kind of fertilizer application we need to boost growth thus making not only a healthier lawn but lowering disease susceptibility in our garden.

Effective Treatments for Lawn Diseases

Lawn diseases can be a homeowner’s nightmare, causing unsightly brown patches or discoloration throughout the lawn. However, with proper diagnosis and treatment, most lawn diseases can be controlled and prevented from spreading.

Using Chemical Treatments

Using chemical treatments is one of the quickest ways of treating pests in your yard. Although effective, it has some downsides which must also be considered:

  • It may take several applications to eradicate the disease.
  • Chemicals may take some time to work on the disease
  • Chemicals may cause harm to beneficial insects like bees and earthworms

However, when used correctly, chemical treatments are an effective solution for treating many types of lawn diseases.

Here are some common chemical treatments for lawn diseases:


Fungicides are commonly used to treat fungi like mildew, leaf spot and blight. There are different types of fungicides available either as sprays or granules:

  • Contact fungicides: These types effectively control fungal damage during early infection phases but require consistent reapplication at weekly intervals.
  • Translocation Fungicides: These types confer systemic protection from plant topside using roots hence providing uninterrupted protection beyond the point of application.
  • Sterol inhibiting Fungicides – SIs inhibit fungal growth by stopping Ergosterol synthesis; hence these fungicides are classified as “preventive” curative“or eradicative” depending on their mode of action.

It’s important that you read instructions carefully while using fungicide products since misuse could lead to health hazards or harmful effects on your grass.

Systemic insecticides

Systemic insecticides can help protect plants, including lawns from pest infestations that often lead to damage.

They contain chemicals that kill insects through direct contact with cuticle or ingestion by piercing/sucking pests like aphids, and mites.

Here are some of the most effective systemic insecticides contain imidacloprid which is applied directly or via spreading granules over your grass bed.

Note that you should read application instructions with care since most systemic insecticides can take several weeks to rid pests thoroughly from your lawn.

Using Natural/Organic Treatments

If you’re looking for an eco-friendly way to treat lawn diseases, organic treatments are a great solution. Although sometimes it takes slightly longer for them to work than chemical treatments, they leave the soil healthier and more fertile.

Here are some common natural/organic treatments for lawn diseases:

Compost teas

Compost tea is rich in nutrients such as nitrogen, phosphorus and potassium as well as beneficial microorganisms that help protect your plants from disease-causing bacteria while also promoting optimal growth rates. You can add compost tea while watering your garden plants or use diluted in a spray bottle to target specific affected areas in lawns with manifestations of brown patches or other signs of pathogen attack.

Neem oil

Neem oil comes from pressed seeds and kernels of the neem tree – an evergreen tree located in Southeast Asia and India. It works by disrupting pest digestive processes without necessarily harming beneficial insects like bees.

You can mix neem oil products with different oils like vegetable oil — e.g., canola or olive oils may impart greater efficacy against certain insects/bacteria combinations before applying on affected lawn parts The best time to apply neem oil according to manufacturers’ advice is late afternoon/evening when sun intensity is less high than noon hours hence reducing foliage burn chances.


Cornmeal products have been found useful in curing certain fungal infections such as powdery mildew leaf spot disease. Application process varies depending on product brand however commonly sold ones require sprinkling around target spots followed by spraying water lightly so it stays within proximity of established roots.

Who to Call

If you’re unsure about what kind of treatment to use, or if the problem persists despite your best efforts, it’s always advisable that you consult a professional lawn care service. A reliable lawn service program would offer tailored health assessments for yards and provide practical recommendations on which treatments are efficient in restoring and preserving the overall health of your lawn. They also have necessary skill set needed to manage weed infestations, fertilization, pH balancing of soils among other crucial aspects you may not have knowledge about as a homeowner.

Final Word

Lawn diseases are common issues homeowners face but can be prevented or managed with the right steps taken at early stages before they become too hard to treat. Identifying signs when they appear is key since prevention is better than cure; promptly rectifying soil disorders alleviates aboveground symptoms faster preventing small problems from growing into massive plagues that involve sound resource commitments to fix.

Common Mistakes to Avoid When Treating Lawn Diseases

When it comes to lawn diseases, maintenance and prevention are key. However, mistakes can still happen during the treatment process that can harm your lawn rather than help it. Here are some common mistakes to avoid when treating lawn diseases:

Misidentifying the Disease

Misidentifying a lawn disease can lead to using the wrong type of treatment, which can make the problem worse or even kill your grass. It’s important to correctly identify what is affecting your lawn before taking action.

One common mistake is assuming that all brown patches in a lawn are caused by a lack of water or nutrients. Brown patches can actually indicate several different types of diseases, such as brown patch or dollar spot.

To properly identify a disease, take a closer look at the affected area. Look for any distinct patterns or shapes on the blades of grass, as well as color changes and irregular growth patterns. You can also take samples to your local garden center or agricultural extension office for proper identification.

Overuse of Chemical Treatments

Chemical treatments can be effective when used correctly, but applying too much or using them too frequently can harm your grass and damage soil health.

One common mistake is over-fertilizing with nitrogen-rich fertilizers as they encourage fast leaf growth, which makes plants more susceptible to fungal diseases. Another chemical mistake is spraying fungicides without having confirmed a fungus infection correctly diagnosed through testing since not all browning spots are fungal diseases.

It’s important only to apply chemicals according to labeled instructions and guidelines from experts in agricultural extensions agencies – never exceed recommended doses.

Moreover, one may choose organic pesticides and herbicides with no harmful chemicals added — companion planting could also aid pest control like having pollinating plants popping around.

Not Following Instructions

It’s essential to follow instructions when treating lawn diseases carefully. Missed steps or incorrect application could compromise effectiveness while putting your groundless on more significant health risks.

Common mistakes here include applying products at the wrong time, not using a calibrated machine for application, and failing to use personal protective equipment as necessary while dealing with chemicals and moldy grass.

Remember that different treatments have specific conditions and temperatures in which they’ll work best. So look out for indications, such as nighttime applications or instructions about how long after treatment one should keep off the lawn and follow them accordingly.

Neglecting Prevention Methods

It’s always better to prevent problems before they occur rather than trying to fix them later. There are several things you can do to prevent lawn diseases, even if your area is prone to some common infections:

  • Mow regularly: regularly mowing your grass encourages strong root growth and air movement in the soil – this prevents fungal infections like brown patches caused by overwatering too
  • Water appropriately: water deeply but infrequently so that grass roots grow tens of centimeters deep into the ground source water below removing boggy thick sods near flowerbeds
  • Improve your soil quality so it holds moisture better—add organic matter like compost or gencrop humus-toned manure.
  • Use resistant turfgrass species when planting new lawns.
  • Identify disease-prone areas of your property early on weeds could harm the healthy growth of your plants.

Prevention is always easier than trying to treat diseases once they’ve taken hold. And who wouldn’t enjoy having a lush green lawn without all nasty blemishes messing up their plate?

By avoiding these common mistakes (misidentification, chemical overuse or abuse & neglecting prevention measures), homeowners can ensure when treating lawn diseases will lead to healthy thriving lawns even after treatment!

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