Natal Redtop or Zizka
Common name
Natal Redtop or Zizka
Scientific Name
Melinis repens
Type of plant
Grasses (Family Poaceae)
About this weed
This tufted perennial or annual grass was photographed at Brixton Street Wetlands and is common on gravelly soils on the eastern part of the Swan Coastal Plain. It was originally a native of South Africa, India, north Africa and parts of the Mediterranean Region and was introduced as an ornamental plant, for forage and to control soil erosion.
Description
Natal Redtop is an aromatic tufted annual or perennial grass growing to 1.2 m high. It produces red to purple flowers in most months except in winter. Reproduction is by seed that is then dispersed by wind and wildlife. After fire the grass resprouts and sets prolific seed. Seeds germinate and grows under a wide range of temperature conditions with rates controlled by temperature when adequate moisture is available. Responds positively to addition of nutrients. It can be affected by mycorrhizal fungi which may play a role in facilitating or repelling invasion.
Impact on Bushland
In its native range it occurs in disturbed open habitats, often forming large stands. It is widely distributed outside its native range. Natal Redtop displaces native vegetation and prevents the natural succession of native species.
Location
Located in various parts of the State in sand, loam and granite soils and along road and rail verges. On the eastern side of the Swan Coastal Plain it is common on gravelly soils.
Priority for removal
Unknown: but if established can impact native plant communities.
Management (hand)
Cut out small populations to prevent seed set. Optimal months for hand weeding are November to April.
Management (herbicide)
Spray 13 ml/L (6.5 L/ha) Fusilade® Forte + wetting agent or for generic fluazifop-p (212g/L active ingredient) 8ml/L or 4L/ha + wetting agent. In less sensitive areas spot spray Glyphosate at 1-2% solution + surfactant prior to flowering and seed set. Following fire is an optimum time to undertake control of populations. Read the manufacturers’ labels and material safety data sheets before using herbicides. Optimal months for spraying are November and December, followed by occasional spraying in January.
Flowering month/s
January, February, March, April, July, August, September, October, November, December
Flower colour/s
Red, Purple
Information source
https://florabase.dpaw.wa.gov.au/browse/profile/14985
Additional information
https://florabase.dpaw.wa.gov.au/weeds/swanweeds/
Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. and Cousens, R.D. (2007) Western weeds. A guide to the weeds of Western Australia, Second Edition, The Weeds Society of Western Australia, Victoria Park, Western Australia.
