Bulbil Watsonia

Watsonia meriana var. Bulbillifera

Bulbil Watsonia

Image credit: Kate Blood

Bulbil Watsonia is a winter-growing bulb widely established in degraded native vegetation and wasteland, and on roadsides, in the Mount Lofty Ranges.

It is a declared weed under the Natural Resources Management Act 2004 (NRM Act).

Description

  • an erect herb that produces dense stands of light green, sword-shaped leaves
  • leaves are generally less than 1 m long and 5 cm wide
  • leaves are produced from a central corm in winter and die off in late summer and autumn, or earlier in dry years
  • flowering stems appear in spring and are slender, reddish and usually less than 2 m tall
  • flowers form in spring and early summer and are orange to red, tubular and 5 to 8 cm long, they rarely produce fruit in Australia
  • reproduction is clonal. Cormils are small, shiny red-brown reproductive buds that develop in clusters at the base of the leaves
  • the cormils are scattered when the leaves die and each one can form a new plant. The corms from which existing plants grow also divide and can create two to three new plants each year.

Impacts

  • an aggressive weed of native vegetation
  • in native woodlands and along watercourses Bulbil Watsonia can form continuous clonal stands that exclude other ground-layer species
  • also invades roadsides, wasteland and unimproved pasture in high rainfall and waterlogged areas
  • only encroaches into pastures that have been ungrazed for extended periods
  • it is suspected of being poisonous, but stock avoid mature plants and are apparently unaffected by young shoots
  • corms and cormils generally survive fire and prolific flowering and cormil set can follow summer fire.

Distribution

  • Bulbil Watsonia is a native of South Africa and was introduced to Australia as an ornamental garden plant
  • widespread in the Mount Lofty Ranges, particularly in the higher rainfall areas
  • grows well on light or heavy, mildly acid to mildly alkaline soils and tolerates moderate waterlogging in winter.

How to control this weed

  • contaminated soil and plant material should be disposed of safely to avoid creating new infestations
  • small infestations in native vegetation can be controlled by spot spraying or wiping foliage with herbicide, although this is labour intensive
  • use of selective herbicide on regrowth after fire is effective and reduces impacts to native plant species
  • for advice on chemical control techniques contact your nearest Natural Resources Centre
  • refer to the 'Weed control handbook for declared plants in South Australia' for advice on chemical control. You can find it on the Biosecurity SA website.

Declarations

The following sections of the NRM Act apply to Bulbil Watsonia in the Adelaide and Mount Lofty Ranges region:

  • 175 (2) Cannot transport the plant, or any material or equipment containing that plant, on a public road
  • 177 (1) Cannot sell the plant
  • 177 (2) Cannot sell any produce / goods carrying the plant
  • 182 (2) Landowner must control the plant on their land
  • 185 (1) NRM authority may recover costs for control of weeds on roadsides from adjoining landowners

More information

For more detailed information download the fact sheet.

Please contact us for advice and assistance with controlling Bulbil Watsonia.

Natural Resources Adelaide and Mount Lofty Ranges