Snow-in-Summer

Overview

• Botanical name: Cerastium tomentosum (‘Snow in Summer’). 

• Common name: Snow in Summer

• Habit: Low‑mounded groundcover, silvery‑grey woolly foliage, topped in late spring/early summer with masses of small white star‑flowers giving a “snowy” look. 

• Size: Typically about 6‑12 inches (15‑30 cm) tall, spreading to around 12‑24 inches (30‑60 cm) or more depending on site. 

• Hardiness: Suitable for cold climates; listed as hardy to around USDA Zones 3‑7 in many sources. 

• Key features: Very low maintenance, excellent for rock gardens, dry slopes, edging; silvery foliage provides year‑round interest even when not in bloom. 

Light & Site Requirements

• Sunlight: Prefers full sun for best foliage colour and blooming. Plants in shade may lose density, colour, and bloom. 

• Soil: Needs very well‑drained soil—especially lean soils (gravelly, sandy) are ideal. Poor drainage is the main cause of failure (root rot).

• Moisture: Once established, it is drought‑tolerant. It does not like soggy or persistently moist conditions. 

• Environment: Performs best in cooler summer climates; in hot, humid regions the plant may struggle or become short‑lived. 

Planting, Watering & Maintenance

• Planting tips:

  • Plant in spring or early fall when soil is workable.

  • Prepare site: loosen soil, ensure drainage; amend heavy clay with grit or gravel if necessary.

  • Space about 12‑18″ apart to allow the mat to fill in. 

• Watering:

  • Until established, water regularly but do not over‑water.

  • After establishment, water only during extended dry spells; allow soil to dry out between waterings.

• Fertilizing: Minimal feeding needed; leaner soil is preferable. Over‑fertile soil may lead to weak, floppy growth. 

• Trimming / Shearing:

  • After flowering, consider shearing back the spent flower stems and maybe trimming the mat to keep it tidy and encourage fresh growth. 

  • Watch for self‑seeding or runners in favourable conditions and trim to control spread if desired. 

• Division / Renewal: If the centre of the mat thins out after a few years, divide and replant in spring or fall. 

Cold‑Climate / Northern Garden Considerations

• Snow in Summer’s hardiness makes it a good choice for northern gardens (Zone 3/4) provided you pick a sunny, well‑drained location.

• Key for success: avoid low spots where winter/spring melt or standing water puddles around the crown. Choose a slope or raised bed if possible.

• Because of the woolly, silvery foliage, it is fairly winter resilient; but ensuring good drainage through freeze‑thaw cycles is important.

• In very exposed or extremely hot summer climates, it may struggle; but in cooler summers (as in many northern zones) it does well.

Photo from gardenia.net