Expert Advice

Pythium Blight/Greasy Spot


Greasy spot occurs most often during very hot and humid weather conditions (June to September). It is known to be the most destructive lawn disease as it can take less than 24 hours to destroy the grass. Symptoms appear as dark green water-soaked grass leaves in circular or irregular patches and are greasy/slimy to the touch.


Make sure to avoid excess nitrogen and over watering. Avoiding prolonged periods of leaf wetness will drastically reduce the severity of greasy spot. Proper irrigation timing is needed to balance these factors. The lawn should be irrigated early in the morning (between 4am-7am) with 1” of water. Avoid excess nitrogen as it can worsen the problem. Mowing height should be at least 3” and a regular fertilization schedule is crucial to give your lawn the nutrients it needs to bounce back.