Arnica (Arnica montana or leopard's bane) is an herb that is native to Europe and Asia. It grows wild in cool, mountainous regions, such as Colorado, up to 8,000 feet in elevation. It's also known as mountain snuff and mountain tobacco. It has narrow grey-green leaves and small, daisy-like flowers that rise on stems up to two feet tall and occur in summer. Herbalists use arnica flower heads in liniments and salves to help soothe sprains, bruises, varicose veins and other conditions. If you live in a fairly cool, mountainous region you should have no trouble growing arnica.
Start your arnica seeds indoors in late summer, using fresh seed if it's available from a local source in your area.
Fill your nursery pot or flat to within ½ inch of its rim with potting soil and then scatter seeds on top. Press the seeds into the soil with your palm but do not cover with more potting soil. Then sprinkle well with a fine mist of water.
Place your flat or pots in an area that receives partial sunlight every day, keep them damp and maintain a temperature of around 55 degrees Fahrenheit. Expect germination to occur in one month.
Transplant seedlings when they are two inches or more tall after your final spring frost. Choose an area that receives full sunlight and has moist, well-drained soil and plant seedlings two feet apart. Because this plant is a wildflower it can grow in poor soil, so you needn't enrich the area with compost before you plant. However, it does prefer a slightly sandy soil.
Limit the amount of nitrogen you give your arnica plants. Refrain from mulching with grass clippings or using any fertilizer that is rich in this plant nutrient because it can cause your plants to become tall and "leggy."
Divide mature plants to create more plants in spring or fall. You can take cuttings to root for new plants during the summer months.