Watch out for yellow patch on putting greens and landscapes

Yellow patch on an annual bluegrass putting green

Given the cool, wet weather we've had over the last few weeks, golf course superintendents should be on the lookout for yellow patch in their creeping bentgrass putting greens. This disease is also known as 'cool-season brown patch', but the symptoms are very different. Yellow patch appears in irregular rings and arcs that are yellow, or sometimes white. Some people say it looks just like sweat rings on an old baseball cap.

Yellow patch can also occur in landscapes established with Kentucky bluegrass or tall fescue. In these cases, the rings are not so distinct but instead has a very irregular appearance. Distinct lesions that are white or light tan with a light brown border can be seen on the affected leaves.

Yellow patch in a Kentucky bluegrass landscape

Yellow patch can be controlled easily with fungicides, but recovery can be slow if the turf is not growing due to cool temperatures. Early detection and treatment is very important for this reason.

Refer to the Disease Management Utility on TurfFiles for a list of recommended fungicides for yellow patch control.