Managing Large Patch With Nitrogen May 19, 2017 By John Daniels, agronomist, Central Region

Applying nitrogen to zoysiagrass during May can help decrease large patch severity.

Large patch is an annual concern for those maintaining zoysiagrass playing surfaces. This troublesome disease can affect the appearance and playability of turf. Even if a facility has a sound preventative fungicide program, it is not uncommon to experience isolated large patch damage during spring after zoysiagrass breaks dormancy. Unfortunately, abnormally wet weather in late April and early May has encouraged a considerable amount of large patch injury throughout much of the Central Region.

The recent stretch of cool, wet weather has prompted many turf mangers to make additional fungicide treatments to limit further large patch infections. For sites that continue to suffer, a little early season nitrogen can help speed recovery.   

Turf managers have traditionally avoided applying nitrogen to zoysiagrass during spring for fear of exacerbating disease damage. However, USGA-funded research at Kansas State University and the University of Missouri have shown no ill effects from early season nitrogen. Zoysiagrass plots that were treated with 0.5 pounds of nitrogen per 1000 square feet during May had less-severe large patch damage and a higher percentage of green turf cover than plots that received nitrogen only during summer. Making an early season nitrogen application could provide a simple, relatively inexpensive solution to a potentially unsightly problem.


Central Region Agronomists:

Bob Vavrek, regional director –

John Daniels, agronomist –

Zach Nicoludis, agronomist –

Information on the USGA’s Course Consulting Service 

Contact the Green Section Staff

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