Hi Garnett,

I am not aware of any natural products that are effective against fireweed. There are also no approved biocontrols available for use in Alaska. Consistent mowing or grazing will help to suppress it over time (preventing it from going to seed) and overseeding/planting other species will also help to suppress it over time (outcompeting it). It is a perennial with a robust root system so any treatment method is going to need to be repeated and will take time to show results. Feel free to contact us with any other questions!