Sorghum halepense (L.) Pers. Johnson Grass
Syn.Pl. 1:101 (1805)

Conservation Code: Not threatened
Naturalised Status: Alien to Western Australia
Name Status: Current

Brief Description
Grazyna Paczkowska, Friday 17 December 1993

Rhizomatous, tufted perennial, grass-like or herb, 0.5-2 m high. Fl. brown, Aug to Dec or Jan to Feb. Loam, sand.


Beard’s Provinces: Eremaean Province, Northern Province, South-West Province.

IBRA Regions: Avon Wheatbelt, Carnarvon, Coolgardie, Esperance Plains, Geraldton Sandplains, Jarrah Forest, Mallee, Swan Coastal Plain, Victoria Bonaparte, Warren.

IBRA Subregions: Avon Wheatbelt P1, Avon Wheatbelt P2, Eastern Goldfield, Geraldton Hills, Northern Jarrah Forest, Perth, Recherche, Southern Jarrah Forest, Victoria Bonaparte P1, Warren, Western Mallee, Wooramel.

IMCRA Regions: Central West Coast.

Local Government Areas (LGAs): Armadale, Bassendean, Beverley, Bridgetown-Greenbushes, Capel, Carnarvon, Christmas Island, Esperance, Gnowangerup, Gosnells, Harvey, Kalamunda, Kalgoorlie-Boulder, Kojonup, Manjimup, Merredin, Mosman Park, Northam, Northampton, Serpentine-Jarrahdale, Swan, Wyndham-East Kimberley.

Management Notes (for the Swan NRM Region)
Kate Brown and Karen Bettink, Monday 26 August 2019

Alternative Names. Means grass.

General Biology. Growth form. Grass. Life form. Perennial, rhizomatous. Reproduction. Seed, rhizome. Dispersal. Explosive dehiscing, wind, water (especially flooding), birds, cattle, other animals, contaminated seed. Photosynthetic Pathway. C4. Toxicity. Occasionally causes cyanide posioning in cattle and horses. Significant cause of hay fever. Seedbank persistence. 5+ years. Fire response. Resprouts.

Notes. Widespread and highly invasive species. Occurs in nutrient-rich habitats and is characterised by intensive nutrient uptake and high growth rates. Can reproduce sexually and asexually. Produces prolific seed which can remain dormant in the soil for up to 20 years. Germinability is highest at 20-30 degrees celsius at soil depths of less than 12 cm. Forms primary, secondary and tertiary rhizomes. Regeneration of a rhizome cutting requires it to have at least one intact node and 2 internodes. Has deep branching rhizomes. Killed by heavy frost.

Additional information. Origin. Mediterranean. History of use/introduction. Contaminated crop seed.

Suggested method of management and control. Spray during first 2 weeks of season's growth with 1% glyphosate or 8 ml/10 L (400 ml/ha) Verdict 520® + wetting agent. Follow-up spot spray and control of seedlings. Should be controlled before rhizomes are formed, generally before 7-leaf stage. Read the manufacturers' labels and material safety data sheets before using herbicides. For further information consult the Australian Pesticides and Veterinary Medicines Authority to determine the status of permits for your situation or state.

Management Calendar

Calendar Type Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Comments
Active Growth Y               Y Y Y Y  
Germination                   U U    
Flowering Y Y                   Y  
Fruiting   U                      
Optimum Treatment                 Y Y Y Y  

Legend: Y = Yes, regularly, O = Occasionally, U = Uncertain, referred by others but not confirmed.



  • Barrentine, W. & McWhorter, C. (1988) Johnson grass (Sorghum halepense) control with herbicides in oil diluent. Weed Science, 36: 102-110.
  • California Department of Food and Agriculture (2001) Encycloweedia: The noxious weeds data sheets. URL: - Accessed December 2007.
  • Conn, J.S. & Deck, R.E. (1991) Bluejoint Reedgrass (Calamagrostis canadensis) control with glyphosate and additives. Weed Technology, 5: 521-524.
  • Essl, F. (2005) Invasion history and phytosociological affinities of Johnson grass (Sorghum halepense) - a case study from eastern Upper Austria. Tuexenia, 25: 251-268.
  • Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. & Cousens, R.D. (2007) Western Weeds. A guide to the weeds of Western Australia. 2nd Edition. The Plant Protection Society of Western Australia, Victoria Park.
  • Mitich, L.W. (1987) Colonel Johnson's Grass: Johnsonsgrass. Weed Technology, 1 (1): 112-113.
  • Moore, C.B. & Moore, J.H. (2002) Herbiguide, the pesticide expert on a disk. Herbiguide, PO Box 44 Albany, Western Australia, 6330.
  • Newman, D. (1990) Element stewardship abstract for Sorghum halepense, Johnson Grass. The Nature Conservancy, Arlington, USA. URL: - Accessed December 2007.
  • Oyer, E.B., Gries, G.A. & Rogers, B.J. (1959) The seasonal development of Johnson grass plants. Weeds, 7 (1): 13-19.
  • Snyder, S.A. (1992) Sorghum halepense. In U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2002, April). Fire Effects Information System. URL: - Accessed December 2007.
  • Toth, V. & Lehoczky, E. (2006) Characteristics of development and nutrient uptake of Johnson grass (Sorghum halepense (L.) Pers.) growing from seed during the first year. Journal of Plant Diseases and Protection, 20: 363-368.
  • Toth, V. & Lehoczky, E. (2006) Investigations on the germination depth of Johnson grass (Sorghum halepense [L.] pers). Communications in Agricultural & Applied Biological Sciences, 71 (3): 803-808.
  • Vrbnicanin, S. & Janjic, V. (2004) Biology, ecology and control of Johnson grass (Sorghum halepense (L.) Pers.). Biljni Lekar (Plant Doctor), 32 (5): 377-383.
  • Webber, R.W. (2004) Johnson grass. Annal Allergy Asthma Immunology, 93 (1): A6.

Project information and acknowledgements