Areas Of Grass Have Purple Colored Powder Coating

Question From: Cedar Springs, Michigan, United States
Q: I have an area of lawn in direct sunlight. I mow to a hieght of 4". Overnight some swaths of grass, within a 10' area have developed purplish powder like coating on the blades of grass. The swaths vary in length but are approximately 9 - 12" wide. When I pick a blade of grass and run it through my fingers, most of the the residue comes off in a powder like fashion on the fingers. Could you help me figure out what it is please?

A: I think you have red thread - a fungal disease. Lack of nitrogen is often the issue, so fertilize with a slow release fertilizer. Best And Happy Yardening, Nancy