Answer: That's really bizarre! Try digging out a small area of the affected turf and examining both the blades and the roots. Look for black or orange colored spots (fungus) on the leaves, excess thatch, dead roots, evidence of insects. Check the soil, too. Is it the same as in the healthy areas of your turf? Different color? Does it have an odor? Are the blades of grass bleached all the way down to the roots? All of these observations can help you diagnose the problem. Here's a website with photos of the most common St. Augustine diseases: http://plantpathology.tamu.edu/Texlab/Lawns/sagtop.html
Hope this helps!
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