Imperata cylindrica

Common Name: cogon grass

Family: Poaceae

Common Synonyms: Lagurus cylindricus

USDA Hardiness Zone: 6a-9b

Growth Habit: Graminoid

Origin: East Africa

FISC Category: 1

FDACS Listed Noxious Weed: Yes

Introduction Date: 1930s

IFAS Assessment:

• North: PROHIBITED
• Central: PROHIBITED
• South: PROHIBITED

Description

Perennial grass, growing in loose or compact tufts, from stout, creeping rhizomes with sharp-pointed tips. Leaf sheaths relatively short, glabrous or pubescent, membranous ligule 0.5-1 mm long. Leaf blades erect, flat, narrow and pubescent at base, to 1.2 m tall and to 2 cm wide, with noticeably off-center whitish midvein. Inflorescence a dense terminal panicle, white silky and plume-like, to 21 cm long and 3.5 cm wide. Spikelets paired on unequal stalks, each spikelet surrounded by long white hairs.

Habitat

Disturbed areas

Comments

Forms extensive monoculture patches over time. Alters ecosystem function, increases fire severity and intensity, increases fire return interval. Requires regular, repeated treatments to control.

Control Methods

• Manual: Mechanical: Burning or tillage in combination with herbicides should be used for optimum control.
• Chemical: Foliar: 3-5% glyphosate with 6-12 mo retreatment interval, 1-2% imazapyr with 8-12 retreatment interval, or a glyphosate (2%)+imazapyr (0.5%) mix with 7-12 month retreatment interval. Repeated treatments required, best to alternate active ingredients in treatments to reduce likelihood of creating herbicide resistance. [IFAS]
• Biological: Dr. Jim Cuda (IFAS) is researching several biocontrol agents

Control Notes

Fluazifop is a selective grass herbicide that provides more flexibility when desirable broadleaf species are present for revegetation. If not controlled, cogongrass will spread along roadways and into pastures, mining areas, forest land, parks, and other recreation areas. Extensive rhizomes must be eliminated for long-term control.

References

IFAS, Center for Aquatic and Invasive Plants. 2013. https://plants.ifas.ufl.edu/plant-directory/imperata-cylindrica/. Accessed June 13, 2017.

NISIC-USDA. 2017. Species Profile: Imperata cylindrica. https://www.invasivespeciesinfo.gov/plants/cogongrass.shtml. Accessed June 13, 2017.

IFAS, Center for Aquatic and Invasive Plants. 2013. Cogongrass, Imperata cylindrica. https://plants.ifas.ufl.edu/plant-directory/imperata-cylindrica/. Accessed June 13, 2017.

Dave's Garden. PlantFiles: Cogongrass, Imperata cylindrica. http://davesgarden.com/guides/pf/go/776/#b. Accessed June 13, 2017.