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lawn care #868512

Asked May 15, 2024, 9:58 AM EDT

Hello-- My wife and I live in Ellicott City, in the Chatham/Valley Mede neighborhood off Rt 40W, where our front lawn has a number of brown circular spots about the entire lawn. I'm wondering if it could be due to grubs, and I wonder if your experience could shed some light on whether it could be another reason, as well as how we might address the issue to return a healthier looking lawn. Thx for your time and expertise. Stephen

Howard County Maryland

Expert Response

It can be difficult to diagnose turf diseases from symptoms of leaf blade die-off alone. However this looks like a disease called Red Thread, especially when fungal hyphae or mycelium (the actual fungal tissue, which can look somewhat fuzzy or threadlike) are visible on the surface of the grass blades. With the weather we have been having this disease has been very common. You can look for mycelium just after a dewy morning, foggy day, or after rain, since it might disappear during drier, warmer, or breezier weather. The appearance of the mycelium can help differentiate some of the diseases whose damage is very similar. Also the appearance of the pinkish hue is leaning towards Red Thread as opposed to grubs or another fungal disease.

Few fungicides will treat this and other lawn fungal infections; most that do among them require application by a certified pesticide applicator if they are restricted-use chemicals. Most well-trained lawn care companies should have one or more certified applicators that can apply pesticides. That said, fungicides are preventative tools only, helping to prevent infection on still-healthy grass foliage, so they cannot cure existing disease. If a pathogen only blights the leaf blades, though, and the crown is unaffected (this is the plant part near the soil surface that generates new growth), then patches may fill back in on their own once the infection subsides due to weather changes or treatment.

It's hard to recommend a particular fungicide to try (assuming one would even be effective, which they aren't for every lawn disease) without being able to confirm which pathogen may be present, especially since you'd want to confirm the disease is listed on the product label, but hopefully it's reassuring to learn that usually it's lawn care practices that can improve the lawn's prognosis without having to rely on chemical intervention. Actions like adjusting irrigation use, testing soil and fertilizing more (within reason and the Maryland law restrictions), or aerating  can all make an impact on reducing disease outbreak vulnerability in the future. The link for Red thread in the beginning will give you some recommendations to help deter the outbreak as well. 

Emily

Much appreciation, Emily, for your time, effort, and clarification.

Best!

Stephen

On Wed, May 15, 2024 at 12:52 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied May 15, 2024, 1:53 PM EDT

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