Traditional perennial herb for muscle pain, hurt tendons, pinched nerves, and other injuries that don't break the skin. In the European herbal tradition, the Arnica used was the rare and sought-after alpine type that doesn't grow well at lower altitudes. However, American herbalism now uses this native species, Arnica chamissonis, which grows easily in the temperate garden. Perennial plants spread by runners. You can grow it in a large tub to contain it if desired, but make sure it doesn't get waterlogged in winter.
Prefers a well-drained location, and living in a hot, dry-summer climate, I give it afternoon shade. The flowers are the part used, and it produces them in profusion in late spring through early summer.Sow in pots that are well moistened and tamped flat. Scatter seed on the surface, press in, then keep cold and moist for a month, either outdoors or in the fridge. Then bring into the light and keep moist. Sprouting will start once the seeds have experienced light and warmth for a couple of weeks.