How to Identify, Prevent and Treat Lawn Disease

When it comes to lawn care, prevention is always easier than treatment. It is important you do everything you can to keep your lawn healthy, full, and green, but if you do run into a problem with your lawn, not to worry, there are steps you can take to get it fixed and prevent any further damage.

5 Common Lawn Diseases and How to Identify Them

The first step in treating a lawn that has been taken over by disease is to identify what kind of disease you are dealing with. All of our tips apply to most of these diseases and are great methods for prevention, but if you are able to nail down the specific disease this will help you narrow down treatment even better.

1. Brown Patch

Grass Types Affected:

• Tall fescue
• Perennial ryegrass
• Bentgrasses
• Kentucky bluegrass
• St. Augustine grass

Brown patches generally show up in the hotter and more humid summer months. It can usually be identified by a large, circular, and somewhat irregular dry and dead-looking spot(s). If the disease has been around for a while, the middle of the patch might start to improve, leaving a ring of dead grass.

2. Red Thread

Grass Types Affected:

• Bermudagrass
• Bluegrass
• Fescues
• Bentgrasses
• Perennial ryegrass

Red thread is generally found in cool and humid environments and is common when soil is deprived of nutrients. This one is easy to identify because you will notice fine red strands coming from the individual blades of grass.

3. Rust Disease

Grass Types Affected:

• Zoysia
• Perennial ryegrass
• Kentucky bluegrass

Rust disease commonly shows up in the late summer and early fall months, especially in areas that do not receive a lot of sun and do not have great aeration. It will less commonly appear in the spring, but if the lawn has not been fertilized correctly, you may see it this time of year as well. Rust disease is identifiable as light-green or yellow patches on the lawn, and up close you might notice orange-yellow rust spores on the grass blades themselves.

4. Snow Mold

Grass Types Affected:

• Ryegrasses
• Creeping bentgrass

Snow mold can come in the form of pink snow mold or gray snow mold. As its name implies, it generally grows underneath snow cover. Pink snow, however, can grow where there is no snow, but it is cool and wet weather. It is usually evident in the early spring months, right after the snow has disappeared. It has a gray-white or white-pink color, and grows in patches that look crusty and matted.

5. Summer Patch

Grass Types Affected:

• Kentucky bluegrass
• Fescues
• Annual bluegrass
• Bentgrass

Summer patch is typically noticeable in June and September, when the humidity is high and the temperature reaches over 85 degrees. It will look like inconsistent brown patches, rings and crescent shapes.

How to Treat & Prevent Lawn Disease

Fertilize Your Lawn the Right Way

If you do not fertilize enough your grass is not going to get the nutrients it needs, and if you fertilize too much you will get growth that is rushed, weak, and might harm the grass. In either case, your lawn is at a higher risk of disease. How often and how much you fertilize depends on a few things.

Fertilizing Factors:

• Type of grass
• Climate
• Amount of water
• Type of fertilizer

Slow-release fertilizers can be applied every 6-8 weeks to maintain a healthy lawn but be sure to follow the instructions on the package and use the proper settings on your spreader.

Cool season grasses: you will want to fertilize lightly in early spring and then heavily in the fall. Avoid fertilizing in the peak of summer when the grasses are likely dormant.

Warm season grasses: apply fertilizer once you see your grass turning green in the spring, and then again just after the peak of summer passes.

Be Smart About Mowing

Mowing different grass types should be cut to different heights, so know which type of lawn you have and avoid cutting more than one third of the length off during mowing. Healthy blade length will help shield the roots from sunshine, encouraging deeper rooting and heat resilience, meaning less chance of disease.

Speaking of blades, always keep your mower blades sharp because dull lawnmower blades will tear the grass rather than cut it, setting your lawn up for disease. You can easily avoid the risk by sharpening your blades at least once a season. If your blades are damaged or over-sharpened, they are also a simple replacement.

If while mowing you suspect any kind of fungal disease in your lawn, collect the clippings and get rid of them rather than leaving them on the lawn or composting them. Keeping them around increases the risk of spreading the disease to other parts of your lawn.

Plan Your Watering Schedule

Early morning watering is best since the rising sun helps to gently dry your lawn. Late morning or early afternoon sunshine will quickly evaporate the water, depriving your grass of the moisture it needs. Rather than watering frequently, water deeply once or twice a week. Wetting the soil to a depth of four to six inches will encourage deeper root growth and resilience to disease. If your sprinklers are on a timer, make sure to adjust the schedule based on how much rain you will be getting each week. This will keep the lawn getting a consistent amount of water.

Dethatch and Aerate Your Lawn

Compacted soil and a thick layer of thatch will restrict water and air, encouraging disease. If this sounds like your lawn, you should aerate twice per year and de-thatch your lawn down to a thickness of about half an inch. If you have a healthy lawn, you should aerate and dethatch once a year to keep it healthy.

Keep Soil at the Proper pH Level

If your soil is high alkaline or overly acidic, your lawn cannot access all the essential nutrients it needs to stay healthy. When this unhealthy grass gets stressed, it is more prone to disease or the growth of undesirable plants like lawn moss. Most lawns do best with slightly acidic soil somewhere around 6.0 to 7.0 pH. You can test your soil each season and adjust get the results you want. If your soil has a low pH, meaning it is overly acid, adding lime can help balance things out. If the soil has a high pH, meaning it is too alkaline, elemental sulfur in granular form is recommended. Ask your local garden center what is right for your lawn.

If your lawn gets to the point where none of these steps will solve the problem, it may be time to call on the professionals to get your grass back in order. If any of your lawn care equipment needs a tune-up, use your model number to shop our extensive library of OEM parts.

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