Annual Bluegrass

Annual Bluegrass, Poa annua, Poa

Poa annua L.

Poaceae (Grass Family)

▲ ▼ young, but flowering plants

▲ ▼ older plants, with lighter green color than surrounding turf

▲ ▼ annual bluegrass growing in a creeping bentgrass golf green (lighter green spots with silvery inflorescences)

Annual Bluegrass:

cool-season annual, sometimes perennial (in northern U.S. states)
short (3/16-6" tall), pale green leaves ending in a keeled tip
silvery-green panicle inflorescence can appear when plant has only 3-4 leaves
can tolerate close mowing (putting green height)
produces many seeds, which may germinate over very long periods of time
Control:
- pre-emergent herbicides, fungicides (rubigan), growth regulators (paclobutrazol)
- difficult to eradicate; once on a site, always need to maintain control practices to keep it from spreading