Cerastium 'Silver Carpet'

Cerastium 'Silver Carpet': Woolly Silver Carpet Sprinkled With Stars

Snow-in-Summer rolls out a silver carpet so plush you'll want to take your shoes off. Then it covers itself in starry white flowers like somebody shook a snow globe over the rock garden. FORGET THE RED CARPET, THIS ONE IS SILVER.

Plant Characteristics:

• Botanical Name: Cerastium tomentosum 'Silver Carpet' (also sold as 'Silberteppich')
• Common Name: Snow-in-Summer
• Height: 15 cm (6 in), about 20 cm (8 in) in flower
• Spread: 45–60 cm (18–24 in)
• Flowers: Small, white, star-shaped flowers covering the plant
• Bloom Time: Late spring to early summer (May to June)
• Foliage: Woolly, silver-grey, narrow leaves forming a dense, low mat; evergreen to semi-evergreen
• Features: Rabbit resistant, handles poor soil

Where to Plant: This is a groundcover for tough places: dry slopes, the tops of retaining walls, rock gardens, gravel beds and the hot strip by the driveway. It spills nicely over edges and between large stones. It spreads readily, so give it room or plant it where its edges are easy to trim back.

Companion Plants: Thymus pseudolanuginosus adds a soft, woolly mat at 2 to 5 cm with pink flowers in June and July. Eryngium 'Blue Hobbit' brings spiky blue flowers from June to August, a fun contrast to the silver carpet. Aster 'October Skies' closes the season with lavender flowers in September and October. All three love full sun and dry, sharp drainage.

Plant Care: Plant in full sun in sandy, gravelly or average soil with excellent drainage. Rich soil makes it floppy, and wet soil, especially in winter, is the main thing that kills it. Water the first season, then let it be. It does not want extra fertilizer. Shear the plant back after flowering to remove spent stems, tidy the mat and stop self-seeding. Leave the foliage over winter and tidy any dead patches in spring. Divide in spring or fall every few years, or pull up stray runners to keep it in bounds.

History: Snow-in-summer is native to the mountains of Italy, including Sicily, and tomentosum means woolly, for the felted leaves. 'Silver Carpet' is the English name for 'Silberteppich', a German selection valued for its silvery colour and a somewhat less aggressive habit than the straight species.

Final Thoughts: Poor soil, hot sun and dry spells don't faze it, and the deer and rabbits keep walking. ROLL IT OUT AND LET IT SPREAD.