(Arnica cordifolia). Zones 3 – 6. Perennial. This species produces large showy flowers, often 2 to 3 per stem, which bloom from May through August.
Arnica is a perennial that grows to a height of 1 to 2 feet with yellow-orange flowers similar to daisies. Stems are round and hairy, ending in one to three flower stalks, with flowers 2 to 3 inches across. Leaves are bright green; the upper surfaces are toothed and slightly hairy while lower leaves have rounded tips. The flowers are used medicinally in salves or liniment for strained muscles and bruises.
Propagation: Arnica prefers a moist, well-drained humus rich soil, preferably lime-free. Sow seed in autumn directly into prepared garden spot. For stored seed, sow early in the spring in a cold frame. Barely cover the seed and make sure that the compost does not dry out. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse or cold frame for their first winter. Plant out in late spring or early summer.