Leontopodium alpinum better known as Edelweiss, is a hardy short lived herbaceous perennial, best suited to rockeries, scree beds and alpine houses.
It grows to around 200mm (8") high with a similar spread, and generally the papery white flowers appear in June / July.
The flowers are hermaphrodite (have both male and female organs)
Sow commercial seed in pots/trays of 50% fine grit and 50% potting compost,
lightly cover, and germinate at a temperature of 18°-20°C (64°-68°F)
Alternatively, sowings of ripe seed collected after flowering, can be made around Week 28-30.
Sow the ripe seed in a similar compost and place in a coldframe to germinate.
If conditions allow plant out previous years seedlings in a sunny well drained, alkaline site.
Leontopodium / Edelweiss resent a wet root system.
Add some grit to planting area when planting out in heavy soil to alleviate this problem .
They will also benefit from some form of overhead cover (cloches) in wet seasons.
Prick out seedlings into individual 70mm (3") pots or cell trays and grow on in a cold frame until planting out time the following year.
With summer sown seeds, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter.
Circa week 28-30:
Lift and divide established plants if required.