Cold hardiness & minimum temperature

Is White Young's Barrenwort (Epimedium x youngianum 'Niveum')cold hardy? Hardiness zone & min temp

Also called White Young's Barrenwort, Snow White Barrenwort, Fairy Wings.

More about white young's barrenwort

About White Young's Barrenwort

Epimedium x youngianum 'Niveum' · also called White Young's Barrenwort, Snow White Barrenwort · flowering

'Niveum' is a compact, elegant Epimedium hybrid producing a profusion of pure white, spurred flowers on delicate wiry stems in spring. Smaller in stature than most Epimediums, it suits shaded rock gardens, woodland edges, and the fronts of shaded borders. Bronze-tinted new foliage matures to fresh green and often takes on autumn colour before winter dormancy.

Cold limit: USDA 4-8 · RHS H6 (-20°C to 28°C)

Watch for — Flowers obscured by overwintered foliage: Even the semi-deciduous leaves of 'Niveum' can obscure delicate spring flowers if not removed. Cut all foliage to within 5 cm of the ground in late February to early March before flower buds open.

What white young's barrenwort's hardiness rating actually means

Yes — white young's barrenwort is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. 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 about −20 to −15 °C. White Young's Barrenwort is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for white young's barrenwort as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 white young's barrenwort 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 white young's barrenwort can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

White Young's Barrenwort hardiness — frequently asked questions

Is white young's barrenwort cold hardy?

Yes — white young's barrenwort is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. White Young's Barrenwort 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 white young's barrenwort can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. White Young's Barrenwort is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is white young's barrenwort?

White Young's Barrenwort is rated USDA 4-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can white young's barrenwort 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 white young's barrenwort below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.