Hello Tom,

It can be difficult to diagnose turf diseases from symptoms of leaf blade die-off alone, and unfortunately the photos are too small and far away from the symptoms for us to make out enough detail. Dieback from different fungal diseases or other conditions 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.) The page linked above may help you to narrow-down possible conditions based on symptoms you can examine up close.

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. (We presume you lawn care service uses certified applicators, though not all do.) 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 grass 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 or the lawn company would want to confirm the disease is listed on the product label. 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.

You mention that the lawn company makes treatments on a schedule, but not what they are treating for and what product(s) they are using. They should only be applying pesticides for known problems that have been previously identified/diagnosed. Routine grub control insecticides, for example, tend not to be needed unless a grub population rises substantially in a particular year. (Even then, repeat applications every year thereafter are probably not necessary, and depending on the chemical used, might harm other beneficial insects that prey on pests in the lawn.)

Animal urine, especially from transient wild animals, is unlikely to be causing any noticeable turf damage. If a dog were to routinely urinate on a specific area, that might cause damage, but that does not sound like the issue here, nor do the pictured symptoms align with that scenario.

Miri