Q.Problem Centipede Grass
Our Centipede grass has several areas of a grayish patch that just appeared last night. The blades look thin compared to the green blades next to them. I have read all of the various fungus symptoms and not sure if any are what I am seeing. The grass is irrigated by a sprinkler system at 3 am four times a week for 30 minutes. These patches do not respond to the liquid disease control used to kill brown fungus that has attacked our lawn. I don’t know what to do. Can you help?
Given that your patches just appeared and were just treated, you may want to give your liquid disease control some more time to work its magic. However, based on your description, you could possibly have large patch caused by Rhizoctonia solani which creates large circular patches of thin grass. Large patch happens in grass with excessive soil moisture. But this diagnosis depends on whether your grayish patches of grass were in circles. Large patch and other reasons for centipede grass problems (along with courses of treatment) are discussed in the following article.
http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/tg1.htm
And here is one more thought - it could be slime mold which can literally appear overnight and is commonly found in centipede grass. Chemicals do not kill slime mold. So, if you do have slime mold, this is why your liquid disease control may have been ineffective. For more information on slime mold, please visit the following link:
https://www.gardeningknowhow.com/lawn-care/lgen/black-substance-on-lawns.htm
