Annual Ryegrass

(Updated: Aug. 22, 2022, 11:03 a.m. By: Mike Vysocka)

Description

Annual ryegrass (Festuca perennis), also referred to as Italian ryegrass, is a bunch-type grass that can be used as a nurse crop for quick cover or for winter overseeding of bermudagrass on low maintenance athletic fields or golf courses. It does not possess the quality of perennial ryegrass and is not recommended for sites where high quality turf is desired. However, it is very inexpensive and can be used on low profile fields such as school, park or recreation sites where winter color is desirable. Its seedhead can be confused with that of quackgrass. Annual ryegrass does not have rhizomes, whereas quackgrass does. Annual ryegrass can be easily confused with tall fescue. However, tall fescue has rough leaf blade margins on the lower 13 - 12 of the leaf whereas annual ryegrass has smooth ones. Tall fescue has non-clasping auricles, whereas annual ryegrass has clasping auricles. The backside of the tall fescue leaf blade is less glossy than that of annual ryegrass.

Annual Ryegrass as a Weed

Cultural Control

Annual ryegrass is a common weed problem in turfgrasses on roadsides in the southeastern United States. Maintaining a dense, vigorous turf is the first step in effective weed control. Cultural and management practices that enhance turfgrass growth generally reduce weed competition and encroachment. First, select adapted turfgrass cultivars for your area and then properly fertilize, mow, and water to encourage dense growth.

Species Data

  • SEEDHEAD / FLOWER
  • VERNATION TYPE
  • LIGULE TYPE
    • membranous; blunt, 0.04 - 0.08 inches (1 - 2 mm) long
      Figure 8
  • GROWTH SEASON / LIFE CYCLE
    • cool season turf or annual weed
  • AURICLE TYPE
  • LEAF BLADE TIP SHAPE
    • sharp-pointed; bright green, upper surface dull, deeply ridged, lower surface smooth, glossy and slightly creased, edges smooth
      Figure 15
  • LEAF BLADE WIDTH
    • 0.1 - 0.28 inches (3 - 7 mm) wide
      Figure 16
  • STOLON PRESENCE
    • absent
  • RHIZOME PRESENCE
    • absent
  • COLLAR TYPE
    • continuous; indistinct, not hairy
  • SHEATH MARGIN
    • split with overlapping margins
  • SHEATH TYPE
    • round; pinkish at the base
Annual ryegrass seedhead
Figure 1. Annual ryegrass seedhead.
close-up of Annual ryegrass seedhead
Figure 2. Annual ryegrass seedhead.
additional close-up of Annual ryegrass seedhead
Figure 3. Annual ryegrass seedhead.
Annual ryegrass seedhead next to ruler
Figure 4. Annual ryegrass seedhead.
Annual ryegrass seedhead next to ruler
Figure 5. Annual ryegrass seedhead.
Annual ryegrass vernation rolled top-view
Figure 6. Annual ryegrass vernation rolled.
Annual ryegrass vernation
Figure 7. Annual ryegrass vernation.
close-up view of Annual ryegrass ligule
Figure 8. Annual ryegrass ligule.
Annual ryegrass auricle
Figure 9. Annual ryegrass auricle.
Annual ryegrass auricle
Figure 10. Annual ryegrass auricle.
Annual ryegrass auricle
Figure 11. Annual ryegrass auricle.
Annual ryegrass auricle
Figure 12. Annual ryegrass auricle.
Annual ryegrass auricle
Figure 13. Annual ryegrass auricle.
Annual ryegrass auricle
Figure 14. Annual ryegrass auricle.
Annual ryegrass leaf blade
Figure 15. Annual ryegrass leaf blade tip shape.
Annual ryegrass leaf blade
Figure 16. Annual ryegrass leaf blade.

This Extension publication can also be viewed at: https://content.ces.ncsu.edu/annual-ryegrass