Cerastium is a mat forming hardy perennial.
It has grey downy leaves and flowers with small starry flowers in either early spring or summer.
It's common names include Chickweed and Snow in summer.
Cerastium tomentosum (Snow-in-summer) by Phil Sellen.
Cerastium alpinum (Alpine Chickweed) by Brewbooks.
Common Names: Chickweed, Snow-in-summer, Mouse eared chickweed, Alpine Chickweed, Common mouse ear.
Life Cycle: Hardy perennial. Winter Annual.
Height: 2 to 18 inches (5 to 45 cm). Mat forming. Tufts.
Native: Temperate regions.
Growing Region: Zones 3 to 9.
Flowers: Species dependent: Early spring or/and summer.
Flower Details: Herbaceous. White. Small. Star-shaped.
Foliage: Grey, silver, green. Downy. Elliptical.
Sow Outside: Cover Cerastium seeds. Start of spring - before the last frost, or towards the end of autumn. Spacing 4 to 18 inches (10 to 45 cm).
Sow Inside: Germination time: one to two weeks. Temperature 65 to 75°F (18 to 24°C). Seven or eight weeks in advance. Transplant outdoors following the last frost or in autumn.
Requirements: Full sunlight or light shade. Soil pH 6.0 to 7.0. Most soils, best results in moist ones. Cut back once flowering has completed. Divide after two or three years to maintain vigour. Propagate: by dividing in the spring in cool regions or the autumn in warmer climes. Cuttings can be taken in the early months of summer.
Miscellaneous: Attractive to many species of moths from the Coleophora genus
It is best to sow Cerastium seeds outdoors in the early spring before the last frost; simply cover the seeds with top soil. They should be planted into an area of the garden that has a moist soil pH of 6 to 7. Snow in the summer prefers to grow in a partially shaded or a sunny part of the garden. If you plan to start Cerastium plants indoors first then they should be started about 7 weeks before they are due to put outside in either autumn or after the last frost of the spring. They usually take between one and two weeks to germinate at a temperature of 18 to 22 degrees Centigrade. Once Cerastium seedlings are ready they should be planted out with a spacing of 15 cm (small species) or 40cm (large species).
Snow in summer and other members of Cerastium are easy to look after, simply cut them back after they have flowers, and divide the plant every three years. If you require more plants then cuttings of Cerastium can be took in the summer.
I hope that you enjoyed this guide on how to grow Cerastium plants. Updated September 2020.