Sorghum halepense (L.) Pers.
Johnson Grass

Syn.Pl. 1:101 (1805)
Conservation Code
Not threatened
Naturalised Status
Alien to Western Australia
Name Status

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

Grazyna Paczkowska, Descriptive Catalogue, 17 December 1993


IBRA Regions
Avon Wheatbelt, Carnarvon, Coolgardie, Esperance Plains, Geraldton Sandplains, Indian Tropical Islands, Jarrah Forest, Mallee, Swan Coastal Plain, Victoria Bonaparte, Warren.
IBRA Subregions
Eastern Goldfield, Geraldton Hills, Katanning, Keep, Merredin, Northern Jarrah Forest, Perth, Recherche, Southern Jarrah Forest, 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)

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.



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