Common Reed (Phragmites australis) Response to Postemergence Herbicides

The invasive biotype of common reed has taken over wetlands and can spread into roadsides, turf, and ornamental sites. Additional control options are needed for managing this biotype in noncrop areas and other sites. In container trials, fosamine, glyphosate, and imazapyr all provided excellent control of common reed. Triclopyr suppressed common reed, with increasing rates improving the growth reduction. Chlorflurenol, primisulfuron, and sulfosulfuron did not suppress common reed growth. In field trials, glyphosate and imazapyr were more effective than fosamine, providing 82 and 93% control, respectively, the following April after either June or September applications. The optimum window of application for glyphosate may therefore include both summer and fall applications, wider than the commonly accepted window of only fall treatments. Fosamine provided greater suppression of common reed when applied in September (68% control) compared to June applications (43% control).