How to Beat Gray Leaf Spot
I had a great post to my Facebook page a few days ago. It was made by a friend who’s been on my page for several years. He’s had a problem with gray leaf spot. Before I copy his post and show you his photo, please let me describe this disease to you. It’s quick and it’s easy.
How to recognize gray leaf spot
• Attacks St. Augustine.
• Shows up in hottest weather (mid-June through mid-September).
• Lawn develops yellowed “washes” that tempt you to apply nitrogen.
• Close inspection shows gray/brown, diamond-shaped lesions on leaf blades and occasionally on runners.
• Grass is decidedly yellowed, not the dry, tan color of chinch bugs, and damage is in all parts of the lawn (sun and shade), not just in sun like chinch bugs.
• But nitrogen only makes it worse, usually very quickly.
• Therefore, you can use fungicides for short-term relief, but the real solution is to stop applying nitrogen during the summer (After June 15 and before September 15). That only applies to St. Augustine.
Here is what Gary Wilson posted on my Facebook page:
I wanted to thank you! For several years I have had a yellowing in my St. Augustine around this time of year and I always poured on the high nitrogen fertilizer. This year I paid attention to your expertise!! No high-nitrogen-fertilizer in July and August. Best results in several years.