BLUEGRASS, ANNUAL

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CULTURAL CONTROL

Management practices that encourage annual bluegrass persistence include: 1) excessively close mowing; 2) shallow, frequent irrigation; 3) poor soil drainage; 4) improperly timed fertilization; 5) aerifying or dethatching during primary periods of germination; 6) use of heavy equipment causing compaction; and 7) shade. 

CHEMICAL CONTROL

Preemergence herbicides applied in the late summer or early fall before annual bluegrass emerges give effective control in home lawns, athletic fields, and golf course fairways, rough, etc.. However, many preemergence herbicides prevent seeding of cool-season turf species in home lawns or overseeding on golf courses. Annual bluegrass can be effectively controlled in dormant bermudagrass with glyphosate, simazine or atrazine. (Simazine and atrazine can also be used in other warm-season turf species).  Recently-registered sulfonylurea herbicides such as Monument, Revolver, and TranXit GTA provide excellent postemergence control in fall or winter in non-overseeded warm-season turfgrass species. All sulfonylurea herbicides exhibit reduced efficacy when applied under cool conditions or when cool conditions are present after application, and this problem is exacerbated with Revolver. An unacceptable level of control may be observed under unfavorable weather conditions. In overseeded turfgrasses, preemergence herbicides such as Barricade applied eight weeks prior to overseeding offer annual bluegrass control.

Preemergence herbicides are not effective on the perennial subspecies which may be more common in bentgrass such as golf course putting greens; however, research suggests long-term use of some plant growth regulators may shift the competition in favor of the bentgrass over the perennial subspecies of annual bluegrass. Therefore, a well-planned program involving plant growth regulators may increase the bentgrass/bluegrass ratio in putting greens. 

© North Carolina State University. This information sheet was prepared by Fred Yelverton, Bridget R. Lassiter, Gail G. Wilkerson, Leon Warren, Travis Gannon, Jenifer J. Reynolds, and Gregory S. Buol. Department of Crop Science, College of Agriculture & Life Sciences, North Carolina State University. Prepared July 15, 2008. Available on-line at www.turffiles.ncsu.edu. This publication was made possible through a grant provided by the Center for Turfgrass Environmental Research & Education (CENTERE) whose purpose is to support worthwhile projects that will benefit both the private sector and the public, and protect the environment.