Snow-in-summer (Cerastium tomentosum) sir-ASS-tee-um toe-men-TOE-sum Genus:  Cerastium Snow-in-summer is great for rock gardens and dry areas, and also works well as a container plant. Plant it on a stone wall for a cascading effect. Snow-in-summer needs room to perform. A single plant can carpet an area as wide as a yard across. After the flowers fade, the silver/grey foliage shines on in contrast to more predictable shades of green. Noteworthy Characteristics:  These plants can be short-lived. Care:  Plant in a sunny spot in well-drained soil. Propagation: 

Sow seeds in spring indoors or after last frost, divide plants in spring or autumn, or sow seeds in autumn after last frost.

Problems: 

 No serious problems other than root rot.

Overview

Height Less than 6 in. Spread 6 in. to 12 in. Growth Habit Spreads Growth Pace Invasive/Aggressive Grower, Moderate Grower Light Full Sun Only Moisture Dry Maintenance Moderate Characteristics Showy Flowers Bloom Time Early Summer, Late Spring, Spring, Summer Flower Color White Foliage Color Silver/Grey Uses Container, Ground Covers, Beds and Borders Style Rock Garden Seasonal Interest Spring Interest Tolerance Drought Tolerant Type Perennials