Appearance Annual bluegrass forms fibrous roots, grows up to 15 inches tall, and develops stems that are prostrate to erect. It may root at lower nodes. The stems and sheaths are flattened and the sheaths are also overlapping. They are flat, soft, and both the upper and lower surfaces are smooth. The tip is boat-shaped.
Annual bluegrass can flower at putting green heights.
Occurrence Annual bluegrass occurs on wet, compacted soils, and in cool temperatures. It responds to intense mowing and fertility and lacks tolerance to environmental extremes. To control annual bluegrass without chemicals, maintain turf health and density through proper culture. Avoid overwatering, over fertilization, and compacted soil conditions. Chemical Control Application Period Apply preemergence herbicides before weed germination ion late summer of early autumn.