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Is this dollar spot? #868352

Asked May 14, 2024, 10:37 AM EDT

Area seems to be growing with this continued wet weather patter. What treatments would you suggest?

Harford County Maryland

Expert Response

It can be difficult to diagnose turf diseases from symptoms of leaf blade die-off alone. While we can't rule out Dollar Spot (though this is rarer on tall fescue than it is on Kentucky bluegrass), dieback from other diseases like Red Thread can look very similar, especially when fungal hyphae or mycelium (the actual fungal tissue, which can look somewhat fuzzy or threadlike) are not visible on the surface of the grass blades. 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.

Few fungicides will treat these 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 or dethatching (though tall fescue doesn't really form thatch, so this depends on the species makeup of your lawn) can all make an impact on reducing disease outbreak vulnerability in the future.

Miri

I’ve since sprayed with a fungicide. We’ll see how things resolve themselves. Thanks

The Question Asker Replied May 28, 2024, 1:09 PM EDT
I’ve applied a fungicide spray.Hope that and some consistence sunshine will do the trick,
. Thanks
Sent from my iPad

On May 28, 2024, at 4:54 PM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied May 28, 2024, 5:55 PM EDT

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