Arnica chamissonis is a perennial herb that grows from a rhizome. In nature, the yellow flowers can be found in wet meadows at low to moderate elevations. Members of the aster family, arnica plants are used in the preparation of hundreds of drugs in Europe and Canada, according to the British Columbia Ministry of Environment. Plant the arnica chamissonis seeds indoors 12 weeks in advance of planting them outdoors, and after the last frost date.
Place peat moss in a container and pour water over it, stirring until the moss is wet. Pour it into the cells in the seeding tray to within 1/4 inch of the rim. Pack the peat moss by hand. Add more, if needed, to within 1/4 inch of the rim of the tray and pack again.
Place the seeds on the surface of the moss in each cell. Cover them very lightly with peat moss. Spray the surface of the moss with water. Keep the peat moist until the seeds germinate.
Set the tray in a well-lit area, out of direct sun, that remains 68 degrees Fahrenheit. The seeds should germinate within 16 days; if they don't, refrigerate the tray for four weeks and then return it to an area that remains 68 degrees.