Sonchus oleraceus L. Common Sowthistle
Sp.Pl. 2:794 (1753)

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

Brief Description
Amanda Spooner, Friday 10 February 2006

Erect annual, herb, to 1.5 m high. Fl. yellow, Jan to Dec. Variety of soils. Weed of waste places & disturbed ground.

Distribution

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

IBRA Regions: Avon Wheatbelt, Carnarvon, Central Ranges, Coolgardie, Dampierland, Esperance Plains, Gascoyne, Geraldton Sandplains, Great Victoria Desert, Hampton, Jarrah Forest, Little Sandy Desert, Mallee, Murchison, Nullarbor, Ord Victoria Plain, Pilbara, Swan Coastal Plain, Victoria Bonaparte, Warren, Yalgoo.

IBRA Subregions: Ashburton, Avon Wheatbelt P1, Avon Wheatbelt P2, Cape Range, Carnegie, Central, Central band, Nullarbor Plain, Chichester, Dandaragan Plateau, Eastern Goldfield, Eastern Mallee, Eastern Murchison, Edel, Fitzgerald, Geraldton Hills, Hamersley, Hampton, Lesueur Sandplain, Mann-Musgrave Block, Mardabilla, Northern band, Carlisle, Northern Jarrah Forest, Ord, Ord-Victoria Plains P1, Perth, Pindanland, Recherche, Roebourne, Rudall, Shield, Southern Cross, Southern Jarrah Forest, Tallering, Trainor, Victoria Bonaparte P1, Warren, Western Mallee, Western Murchison, Wooramel.

IMCRA Regions: Abrolhos Islands, Central West Coast, Eucla, Leeuwin-Naturaliste, Pilbara (offshore), Shark Bay, WA South Coast, Zuytdorp.

Local Government Areas (LGAs): Albany, Armadale, Ashburton, Augusta-Margaret River, Bayswater, Beverley, Boddington, Bridgetown-Greenbushes, Broome, Bruce Rock, Bunbury, Busselton, Cambridge, Capel, Carnamah, Carnarvon, Chapman Valley, Chittering, Cockburn, Collie, Coolgardie, Coorow, Corrigin, Cuballing, Cue, Dalwallinu, Dandaragan, Dardanup, Denmark, Donnybrook-Balingup, Dundas, East Pilbara, Esperance, Exmouth, Gingin, Gnowangerup, Goomalling, Gosnells, Greater Geraldton, Halls Creek, Harvey, Irwin, Jerramungup, Kalamunda, Kalgoorlie-Boulder, Kent, Kondinin, Koorda, Kulin, Kwinana, Lake Grace, Laverton, Leonora, Mandurah, Manjimup, Meekatharra, Melville, Menzies, Merredin, Mingenew, Moora, Morawa, Mount Magnet, Mount Marshall, Mundaring, Murray, Nannup, Narrogin, Nedlands, Ngaanyatjarraku, Northam, Northampton, Perth, Pingelly, Ravensthorpe, Rockingham, Shark Bay, South Perth, Swan, Trayning, Upper Gascoyne, Victoria Plains, Vincent, Wanneroo, Waroona, West Arthur, Westonia, Williams, Wiluna, Wongan-Ballidu, Woodanilling, Wyalkatchem, Wyndham-East Kimberley, Yalgoo, Yilgarn, York.

Management Notes (for the Swan NRM Region)
Kate Brown and Karen Bettink, Thursday 21 December 2017

General Biology. Growth form. Herb. Life form. Annual. Reproduction. Seed. Dispersal. Wind. Seedbank persistence. 1-2 years.

Notes. May be biennial. A single plant may produce up to 8,000 seeds. Seed is able to germinate all year round over a broad range of temperatures and is favored by light, with emergence highest in seed present on the soil surface. Resistance to herbicides such as chlorsulfuron and atrazine has led to Sowthistles, including Sonchus oleraceus, being the target of biological control programs overseas and in Australia. Preliminary surveys for suitable control agents found two potential organisms: a rust fungus and eriophyid mite. Hybridises with S. asper.

Additional information. Similar exotic species. Sonchus asper. Similar native species. S. hydrophilus.

Suggested method of management and control. Remove small and/or isolated populations manually prior to seed set. Slashing is often ineffective as flowers continue to be produced. Spot spray Lontrel® 10 ml/10 L + wetting agent preferably at the rosette 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
Germination       O Y Y Y Y          
Active Growth         Y Y Y Y Y Y Y    
Flowering                 Y Y Y Y  
Fruiting Y                   Y Y  
Manual Removal           Y Y Y Y Y O    
Herbicide Treatment           Y Y Y O        

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

 

References

  • Anon. (2002) Weed control in Tasmania’s forests; information sheet 6. Thistles. URL: http://www.forestrytas.com.au/uploads/File/pdf/forest_health_leaflets/weed_identification/weedinfosheet6thistles.pdf - Accessed December 2007.
  • Barber, H.N. (1941) Spontaneous hybrids between Sonchus asper and S. oleraceus. Annals of Botany, 5 (18).
  • Brown, K. & Brooks, K. (2002) Bushland Weeds: A Practical Guide to their Management. Environmental Weeds Action Network, Greenwood.
  • Chauhana, B.S., Gill, G. & Preston, C. (2006) Factors affecting seed germination of annual sowthistle (Sonchus oleraceus) in southern Australia. Weed Science, 54 (5): 854-860.
  • CSIRO Entomolygy (Undated) Management and control of sowthistles in Australia. CSIRO Entomology, Wembley WA. URL: http://www.csiro.au/science/SowthistleControl.html.
  • 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.
  • Hutchinson, I., Colosi, J. & Lewis, R.A. (1984) The biology of Canadian weeds. 63. Sonchus asper (L.) Hill and S. oleraceus L. Canadian Journal of Plant Science, 64: 731-744.
  • Moore, C.B. & Moore, J.H. (2002) Herbiguide, the pesticide expert on a disk. Herbiguide, PO Box 44 Albany, Western Australia, 6330.
  • St. John-Sweeting, R.S., Preston, C., Baker, J., Walker, S. & Widderick, M. (2008) Gene movement in herbicide resistant sowthistle (Sonchus oleraceus L.). In Proceedings of the 16th Australian Weeds Conference, Cairns Convention Centre, North Queensland, Australia, 18-22 May, 2008. 2008. 113-115.
  • Swarbrick, J.T. & Skarratt, D.B. (1994) The bushweed 2 database of environmental weeds in Australia. The University of Queensland, Gatton College.
  • Tamar Valley Weed Strategy (1997) Sow and Prickly Sow Thistles (Sonchus oleraceus and Sonchus asper ssp. glaucescens). Dept. of Primary Industries, Water and the Environment, Tasmania. URL: http://www.weeds.asn.au/tasmanian-weeds/view-by-common-name/sow/ - Accessed May 2010.
  • Widderick, M., Walker, S. & Sindel, B. (2004) Better management of Sonchus oleraceus L. (common sowthistle) based on the weed's ecology. In Weed management: balancing people, planet, profit: Australian Weeds Conference, 14th, 6-9 September 2004, Wagga Wagga NSW.

Project information and acknowledgements