Chamerion angustifolium, commonly called Fireweed, since it is an early colonizer after wildfires, is found across North America in all but the southeastern U.S. Its native range includes a wide range of average annual precipitation, so it should do well in the moderately watered home garden or landscape.
Fireweed flowers are a brilliant magenta to purple color on tall racemes, the stems reaching 6 feet in some locations. In Wyoming I usually see it from 18 to 36 inches tall. It prefers full sun, but can be found in light shade, although with fewer blooms.
Fireweed is a great native flower for attracting hummingbirds to your garden, but be forewarned, that sweet nectar is also appreciated by deer, elk, and antelope.
In its natural habitat, Fireweed’s windblown seeds can travel miles; helping it to become an early species on disturbed areas and along roadsides. When colonizing forested areas after a clear cut or burn, it can become quite dominant until the canopy begins to shade it out.
To propagate Chamerion for home use be sure to obtain fresh seed. Seed viability declines rapidly after two years. One flower can produce hundreds of seed, so if you find a native stand, a few flowers will produce all the seed you need.* Of course always check with your local public land managers and private land owners to get permission to collect wild seed.