(Also known as Mist Flower)

Ageratina riparia

Family: Asteraceae

Type of weed:

Priority Weed Local Priority Weed. (See more weeds of the class.)

Flowering Months: , ,


Mistflower is a straggly perennial growing to 1 m with lanceolate leaves.

It has delicate white tubular flower heads in summer.

A mature plant can produce 10,000 to 100,000 seeds per year. Seeds are 2 mm long with tufts of fine white hair.

Mistflower is almost identical to Crofton Weed but with more delicate flowers. Crofton Weed is more erect and has trowel-shaped leaves.


Seed is dispersed by wind and water over long distances.

Impact on bushland

Mistflower spreads easily along creek lines frming dense stands than can exclude other plants.


, . In sheltered, wet areas such as creeklines.

Alternative planting

Native plants

Alternative plantings to hold soils on creekbanks or stormwater drainage lines include ferns, sedges and rushes such as:

  • Fishbone Water Fern (Blechnum nudum)
  • Prickly Rasp Fern (Doodia aspera)
  • Common Ground Fern (Calochlaena dub)
  • Broad Rush (Juncus planifolius)
  • Common Rush (Juncus usitatus)
  • Tall Sedge (Carex appressa)

Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.

There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.


Specific control tips for this weed


  • Most plants can be hand pulled easily, particularly when the ground is moist. Make sure all roots are removed. When hand removal is not possible, or there is a concern about destabilising creek banks, then cut and paint the plant.
  • Spray low, dense patches.

Remove and dispose of flowers. Cut material can spread out to dry off the ground. Once dead, the material will decompose in place. It is best to treat Mistflower before it flowers, to avoid spreading seeds.

Refer to the NSW Department of Primary Industry’s Noxious and Environmental Weed Control Handbook.

For key points on these techniques:

Local Priority Weed

Control measures:

  • The plant should be fully and continuously suppressed and destroyed.
  • Plants under 4 metres in height should be fully and continuously suppressed and destroyed.
  • The spread of this plant should be adequately contained to prevent spread impacting on priority assets. Weed notices will only be issued for these weeds under special circumstances.

For more info

For key points on these techniques: