Featured weeds

Check out these facts about pest weeds located in the Lockyer Valley.

​Water Hyacinth


With the warmer weather now here and the recent spring rainfall the region has received, residents are being warned to be on the look-out for water weeds.

Water Hyacinth was a major issue in waterways world-wide, with the Lockyer Valley no exception.

  • Water Hyacinth features bright green leaves between five to 10cm in width and light purple flowers.
  • It is a floating water weed that creates a seed bank that can last up to 15 years, so regular treatment and monitoring is essential.
  • Infestations of Water Hyacinth clog waterways and dams and choke out native species, deplete oxygen levels and allow mosquitoes to breed.
  • It is virtually impossible to fish or swim, recreationally, when water weeds are present.

Water Hyacinth can be controlled by hand in small infestations, before flowering or with targeted use of herbicide.



​We all know looks can be deceiving, and that certainly applies to Fireweed.

The aggressive weed, native to Madagascar and southern Africa, has the ability to severely impact agriculture in the Lockyer Valley if it’s not removed from pastures.

  • Fireweed can be identified by its distinctive 13-petal flower, which can rapidly reproduce, dispersing tiny seeds if sprayed by pesticides.
  • Fireweed seeds can move easily with both wind and through grazing cattle.
  • While it’s only a small plant, its impact on grazing cattle is enormous, in some cases leading to death.

If you would like assistance in identifying restricted matter, contact the Environment and Pest unit.



​As the name suggests, Mother-of-millions is a plant that’s hard to eradicate.

Native to Madagascar, these invasive plants are found in various areas of the Lockyer Valley, including Forest Hill, Glen Cairn, Blenheim and Murphys Creek.

  • Mother-of-millions are smooth, fleshy succulent plants growing to one metre or more in height.
  • The leaves and plantlets of Mother-of-millions may be dislodged and spread by animals, vehicles, machinery, soil and slashers.
  • These plants, especially their flowers, are poisonous to stock and occasionally cause a significant number of cattle deaths.

If you would like assistance in identifying restricted matter, contact the Environment and Pest unit.

​Giant rat's tail grass (GRT)


​Giant rat’s tail grass (GRT) is a problematic pest on many levels.

The robust plant features tough leaves and is often taller than
other pasture and native grasses.

  • GRT can grow close to 1.7 metres in height.
  • It has the ability to change shape during its lifetime, from a rat’s tail shape to an elongated pyramid.
  • It overpowers desired pasture grasses and results in the degradation of natural areas.
  • It also reduces pasture productivity, which impacts on the health of cattle.
  • GRT can produce up to 85,000 seeds per square metre in a
    year, with a significant portion of seeds remaining viable for up to 10 years.
  • Seeds can be spread by livestock in manure and on fur and hooves, as well as vehicles and machinery.

GRT is a restricted invasive plant under the Biosecurity Act 2014 and is native to Africa.



​Parthenium is listed as a Weed of National Significance and is characterised by pale green leaves covered with fine soft hairs and small creamy white flowers on the tips of many of its stems.

  • Each flower also contains four to five black seeds. It is an annual herb with a deep tap root and an upright stem that becomes woody with age.
  • Seeds of the Parthenium plant are spread easily byvehicles and machinery. The movement of animals such as livestock, native fauna and pests, as well as water, contaminated stockfeed and seed, spreads the invasive seed.
  • In drought conditions, the spread of seed is heightened due to the increased movements of stock fodder and transport, so given the current dry conditions it’s a weed many need to be wary of.

Contact with the Parthenium plant or pollen can also pose health problems and allergic reactions, such as dermatitis and hay fever.

Its presence reduces the reliability of improved pasture establishment and also reduces pasture production potential. Parthenium is a restricted invasive plant under the Biosecurity Act 2014.

​Annual Ragweed


Native to North America, Annual Ragweed is a fern-like plant that is detrimental to the environment.

  • Fast-growing, the weed often hampers agricultural
    production as it can choke out overgrazed pastures.
  • Annual Ragweed grows between 1 to 2m in height.
  • It features a flower spike up to 20cm long with yellow flowers when mature and small, black seeds.
  • Annual Ragweed was highly allergic.

Council recommends you wear personal protective equipment, such as eye wear, long-sleeve clothing and masks at all times when pulling up Ragweed, as its pollen can often aggravate health concerns, including hay fever and asthma.

Like many weeds, Annual Ragweed spreads easily by
stock, fodder, in floodwater and in soil from infected

Page reviewed: 26 Aug 2020 4:50pm