TURF TIPS Turfgrass Tips is a service of the Illinois Turfgrass Foundation and UIUC Turfgrass Group. May 2002, No. 2 WHAT HAPPENED TO THE COLOR OF BENTGRASS? Frost dessication of a bentgrass sward. Reddish brown color and thinning of a clone of bentgrass which is not very frost tolerant. Individual lesions of Helminthosporium leaf spot on Kentucky Bluegrass.