Leontopodium alpinum, commonly called edelweiss, is a species of low-growing plant that thrives in high alpine environments and harsh mountainous conditions. Leontopodium alpinum is a herbaceous perennial with wooly looking foliage and pale white flower bracts that resemble daisies. Native to southern and central Europe, this plant was immortalized in the song Edelweiss, written by Rogers and Hammerstein for The Sound of Music. Leontopodium alpinumis best suited for rock gardens in cool and cold climates. It is in the family Asteraceae and is closely related to the daisy.
The individual plants grow 6 to 12 inches (about 15 to 30 cm) tall in clumps 6 to 9 inches (about 15 to 22 cm) wide. The plants grow in a gradually expanding colony that spreads from underground rhizomes as well as from seed. The flower bracts are white and grow up to 4 inches (about 10 cm) across, while the actual flowers are tiny yellow blooms tucked into the petal-like bracts. The flower bracts have a soft wooly appearance set against the silver-green foliage.
Leontopodium alpinum thrives in rocky, gritty soil with good drainage, making it an ideal choice for rock gardens and rockeries. It is also well suited as a border plant in rocky soil or planted in mass as a ground cover in raised beds. The flowers bloom in late summer and last into early fall. In areas that experience heavy frost in winter, the foliage dies back and reemerges in the spring. Leontopodium alpinum can not survive in hot, humid or excessively wet conditions.
As with all alpine and high altitude plants, Leontopodium alpinum can withstand poor soil, cold temperatures, wind and harsh sunlight. Though fully adapted to these conditions, the plants grow slowly in response to the harsh environment. This coveted plant is often collected from wild areas, leading to its slow disappearance from much of its native range. The delicate nature and slow growing characteristics of Leontopodium alpinum combined with human disturbance has put the plant on the protected species list.
Domestic plants are propagated from seed and from division of the rhizomes. The seeds are collected in the fall and planted immediately in a cold greenhouse. The seeds require a winter of freezing temperatures in order to germinate in the spring. The seedlings should be grown for the first year in a cool protected environment and then planted outdoors in the spring of the second year. Division of the rhizomes in spring is an alternate way to propagate Leontopodium alpinum.
