Weed control in fine fescue naturalized areas is a frequent discussion topic amongst turf professionals. A combination of preemergence herbicides, broadleaf weed herbicides, and grassy weed herbicides are often used to deliver conditions that meet golfer expectations. Mixing products for application can certainly improve efficiency, but there must be an understanding of how certain products interact to ensure efficacy is not reduced.
Herbicides such as sethoxydim, fluazifop and fenoxaprop can be used for grassy weed control in fine fescue naturalized areas. However, superintendents must be aware of the antagonistic effect that develops when these herbicides are mixed with a broadleaf weed control product that contains MCPA or 2,4-D. When an herbicide containing MCPA or 2,4-D is going to be used for broadleaf weed control and sethoxydim, fluazifop or fenoxaprop is used for grassy weed control, these applications must be made separately. It is best to wait at least seven days between applications if 2,4-D or MCPA is applied first and at least two days between applications if sethoxydim, fluazifop, or fenoxaprop is applied first (Patton).
Weed control applications in fine fescue naturalized areas are just one component of a management program that will help deliver conditions that meet golfer expectations. There are a number of factors – some that can be controlled and others than cannot – like soil type and weather, that must be considered when setting realistic expectations for these areas.
For assistance with developing a management program for naturalized areas and setting realistic expectations, contact your regional USGA agronomist to learn how a Course Consulting Service visit can be structured to address your specific needs.
Reference: Patton, 2020. Turfgrass weed control for professionals. Purdue University Extension
Central Region Agronomists:
Paul Jacobs, agronomist – pjacobs@usga.org
Zach Nicoludis, agronomist – znicoludis@usga.org