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Snow-in-Summer
Cerastium tomentosum
Snow-in-Summer blooms from May through June.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Snow-in-Summer
Plant it in full sun. It prefers low water. It is hardy in USDA zones 3–7. Expect it to reach about 6 in tall and 12 in wide at maturity, in roughly 2 years (not yet checked).
No toxicity note is on file for Snow-in-Summer. That is not a clearance: check its safety for people and pets before planting.
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Snow-in-Summer
Plant Snow-in-Summer in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 5, the middle of its hardy zones 3 to 7, spring means April to June and fall means August or September. Once settled, it blooms from May to June.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 5, the middle of this plant's hardy range, start with zone 5 in April. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Snow-in-Summer get?
6 intall5 ft 7 inan adult12 inwideSee Snow-in-Summer in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Snow-in-Summer
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Snow-in-Summer about 12 in apart, center to center, so each plant has room to reach its full width.
Add Snow-in-Summer to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Snow-in-Summer's height, spread, hardiness zones, sun and trait tags were checked against 2 published sources on July 29, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Missouri Botanical Gardenheight, spread, hardiness zones, sun and trait tags
- NC State ExtensionPlant Toolboxheight, spread, hardiness zones, sun and trait tags
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Snow-in-Summer
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note. A note reports what its source says; where that differs from a fact above, the fact above is this entry's stored value, and its mark says whether it has been checked.
Worth knowing
The usual way to lose it is overwatering, not drought. The lean, gritty, fast-draining soil that prevents fatal root rot is exactly what makes it drought tolerant. per NC State and Missouri Botanical
Spreader or short-lived?
In cool-summer regions it is an aggressive, weedy runner that needs managing; in hot, humid-summer regions the same plant is weaker, short-lived and not invasive. per Colorado State and Missouri Botanical
Evergreen only where cool
NC State rates the mat broadleaf evergreen, but Missouri Botanical finds it thins and melts out in hot, humid summers, so year-round cover holds only where summers are cool. per NC State and Missouri Botanical
Put its vigor to work
A workhorse for hot, dry, sunny problem spots: dry banks and slopes, walls to cascade over, gravelly hell strips, rock gardens and edging, and xeriscape groundcover on poor soil. per NC State and Colorado State
Shear back after flowering
Cut the whole mat back hard right after the late-spring flush. It keeps the mat dense, stops self-seeding, and slows the summer foliage decline. per NC State and Missouri Botanical
Deer usually leave it alone
Deer generally pass it by; the woolly, hairy foliage is the likely reason. As always, no plant is truly deer-proof under heavy pressure. per NC State and Wisconsin
An ornamental chickweed
It is a mouse-ear chickweed in the pink family, an ornamental cousin of the common lawn and field chickweeds. Hence one name: wooly mouse-ear chickweed. per NC State
What pairs well with Snow-in-Summer
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Butterfly Bush
Shares full sun and low water; overlaps, then carries the display into early fall; stands well above at 6.5 ft, a canopy to plant beneath; a soft color beside the white.
Forsythia
Shares full sun and low to moderate water; blooms in early spring, before this one opens; stands well above at 6.5 ft, a canopy to plant beneath; a soft color beside the white.
Obedient Plant
Shares full sun and low to moderate water; blooms in late summer, extending the bed's season; stands well above at 3.5 ft, a canopy to plant beneath; a soft color beside the white.
Potentilla
Shares full sun and low water; overlaps, then carries the display into early fall; taller at 3 ft, for the layer behind it; a soft color beside the white.
Bee Balm
Shares full sun and low to moderate water; blooms in midsummer as this one finishes; taller at 3 ft, for the layer behind it; a soft color beside the white.
Hybrid Tea Rose
Shares full sun and low to moderate water; overlaps, then carries the display into mid fall; stands well above at 4 ft, a canopy to plant beneath; a soft color beside the white.
Maiden Grass
Shares full sun and low water; blooms in early fall, extending the bed's season; stands well above at 6 ft, a canopy to plant beneath; a soft color beside the white.
Russian Sage
Shares full sun and low water; blooms in midsummer as this one finishes; stands well above at 4 ft, a canopy to plant beneath; a soft color beside the white; this one spreads, so it will crowd its neighbor in time.
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