Published by Brian Wagner on 11/10/25 in “Growing Flowers from Seed.”
Cerastium tomentosum (commonly called snow-in-summer) is a member of the Caryophyllaceae (pinks) family and is an alpine perennial hardy to Zone 3. Native to the mountains of Europe (especially France and Italy), it is often called Snow-In-Summer because its springtime flowering produces a vast mat of white flowers ontop of silver foliage. It is truly a sight to see.
The plant is happiest in cooler climates than in hot ones, but it can tolerate drought fairly well. It is happiest in an alpine habitat, but is adapted to scrubland habitats equally well. It has a sprawling habit and will dangle off the edge of rock walls. It is somewhat untidy much of the year, but it seems to come back to life every spring. If the stems get brown and dry, you can simply bury them and they will root.
Growing from Seed
Seeds are suspected to have a non-deep physiological dormancy and should be surface-sown and provided with light, at temperatures around 15C (60F). Care should be given to avoid temperatures above 25C (80F) which may inhibit germination. Seeds may need 2 weeks to germinate, and they are a bit slow in their first month of growth – but will need potting up around Day 60. By Day 90 small plants can be placed outside in the garden.