Cold hardiness & minimum temperature

Is Greater Stitchwort (Stellaria holostea)cold hardy? Hardiness zone & min temp

Also called Greater Stitchwort, Addersmeat, Easter Bells, Shirt-buttons.

More about greater stitchwort

About Greater Stitchwort

Stellaria holostea · also called Greater Stitchwort, Addersmeat · flowering

Greater stitchwort is a delicate but vigorous perennial wildflower native to woodland edges, hedgerow banks, and grassy lanes across Europe. It favours partially shaded, moist but well-drained soils with a neutral to mildly acidic pH, and its bright white star-shaped flowers are a classic sign of spring. The most important care fact is that stems are brittle and need surrounding plants or a support structure to scramble through; avoid disturbing the root zone once established. No serious toxicity to cats or dogs is documented; classified mildly-toxic as a precaution pending confirmed ASPCA listing.

Cold limit: USDA 4-8 · RHS H7 (-25 to 22°C)

What greater stitchwort's hardiness rating actually means

Yes — greater stitchwort is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 4-8 — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly below about −20 °C. Greater Stitchwort is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for greater stitchwort as it gets too cold:

It tolerates winter lows to about −20 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can greater stitchwort go outside or overwinter — and where?

Plant it out within USDA 4-8 and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when greater stitchwort can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Greater Stitchwort hardiness — frequently asked questions

Is greater stitchwort cold hardy?

Yes — greater stitchwort is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Greater Stitchwort is hardy across USDA 4-8; it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature greater stitchwort can survive?

Minimum survivable temperature is roughly below about −20 °C. Greater Stitchwort is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is greater stitchwort?

Greater Stitchwort is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can greater stitchwort survive winter outside?

Plant it out within USDA 4-8 and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to greater stitchwort below its minimum temperature?

It tolerates winter lows to about −20 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.