Is there a fungus among us?
Hot temperatures are already here and with summer months Virginia's hot weather brings the disease Rhizoctonia Solani commonly referred to as Brown Patch. All varieties of Tall Fescue are susceptible to the disease. Brown Patch first appears in small brown circular patches. During the summer months of June, July and August the patches will grow in size; Brown Patch builds up during the day and is killed off naturally when night temperatures drop below 68 degrees. Hot – moist evenings will contribute greatly to Brown Patch, therefore it is recommended to water in the morning to avoid this. Evening summer storms and heavy rain can make this difficult to avoid. If the temperature does not fall below 68° it will continue to grow. The disease mostly affects the leaves but can also affect the shoots. The disease grows best in sunny areas; shady cooler areas are not as big a problem. The disease does not grow in September because the nights are typically much cooler.
Ideally a Preventative Fungicide should be applied June 1st – even though there are no signs of the disease. Brookmeade’s owner Louis Brooking says "It’s going to get hot." Central Virginia is prone to get brown patch. VA Tech’s Agronomy Department performs test plots annually at Brookmeade to study and work on treatment for brown patch. Blacksburg’s colder conditions limit the onset of Brown Patch for research.
Check with your local extension agency, Southern States or The Turf Store for Fungicide Products to treat Brown Patch. Fungicide lasts only 28 days, depending on the conditions you may need to reapply. Based on the previous hot summers we have had in Virginia you should anticipate conditions favorable to Brown Patch disease. Apply an antifungal product designed to prevent and treat it now.