Control Fireweed effectively this season

With paddocks across the region scattered with bright yellow, Fireweed is up and going once again this season.

Classified as a noxious weed due to its strong ability to invade and take over pastures as well as poison livestock, a single Fireweed plant can produce up to 30,000 seeds in a season - making it extremely hard to control and eradicate. The plant contains alkaloids that are toxic to stock if consumed, leading to liver damage (with prolonged exposure). With many farms having bought in supplementary fodder during the recent drought, imported hay, silage and grain feeding sites must be monitored closely for weed germinations.

The best time to treat and control Fireweed is late autumn/early winter - this is when the plants are actively growing & the number of seedlings & young plants peaks. As plants mature later in winter, herbicides are much less effective - slashing/mulching of Fireweed at this time can trigger the plants to regrow, allowing them to survive well into summer and making next season's control much harder.

Vigilance & consistent monitoring must be maintained year round, as some Fireweed plants have been noted to flower earlier or later than normal.

Options for effective control include:

  • Chemical options such as Bromicide 200 (WHP 8 weeks), Minder, Grazon Extra or Hot Shot for Fireweed plants at various stages of plant growth. Consult with local Norco Agronomist or sales team member to find the most suitable chemical fit. Most of these options will often kill legumes however, Bromicide 200 is the softer option, giving legumes the greatest chance of surviving. Various methods of application include boom spraying, spot spraying and wick wiping.
  • Slashing and mulching can also be useful in controlling the spread of Fireweed and should be done before late spring. Be sure to wait two weeks before grazing the slashed or mulched areas, as livestock are more likely to graze the wilted plants.
  • Hand weeding is effective, however, ensure you wear gloves to minimise exposure to alkaloids. Do not weed if the entire root system cannot be removed. Make sure to bag and safely dispose of the weeded plants.

Have a question relating to Fireweed or another subject? Head into your your local Norco Rural Store to consult with one of our expert Agronomists, who will be more than happy to discuss your particular query.