Cold hardiness & minimum temperature

Is Long-stalked Spiderwort (Tradescantia longipes)cold hardy? Hardiness zone & min temp

Also called Long-stalked Spiderwort, Wild Crocus.

More about long-stalked spiderwort

About Long-stalked Spiderwort

Tradescantia longipes · also called Long-stalked Spiderwort, Wild Crocus · flowering

Tradescantia longipes is a low-growing, clump-forming native perennial endemic to the rocky, wooded slopes of the Ozark Mountains of southern Missouri and northern Arkansas. It produces deep blue-violet three-petalled flowers with fringed yellow stamens on long, slender stalks in succession from April to June, then the foliage dies back significantly after bloom. The most important care point is that it needs partial to full shade and consistent moisture to replicate its Ozark woodland habitat. As with other Tradescantia species, treat as mildly toxic to pets given the ASPCA listing of T. fluminensis in the genus.

Cold limit: USDA 4-9 · RHS H6 (-25°C to 32°C)

What long-stalked spiderwort's hardiness rating actually means

Yes — long-stalked spiderwort is genuinely cold hardy. Rated RHS H6 and USDA 4-9, 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 4-9 — 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. Long-stalked Spiderwort is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for long-stalked spiderwort 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 long-stalked spiderwort go outside or overwinter — and where?

Plant it out within USDA 4-9 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 long-stalked spiderwort can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Long-stalked Spiderwort hardiness — frequently asked questions

Is long-stalked spiderwort cold hardy?

Yes — long-stalked spiderwort is genuinely cold hardy. Rated RHS H6 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Long-stalked Spiderwort is hardy across USDA 4-9; 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 long-stalked spiderwort can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Long-stalked Spiderwort is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is long-stalked spiderwort?

Long-stalked Spiderwort is rated USDA 4-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can long-stalked spiderwort survive winter outside?

Plant it out within USDA 4-9 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 long-stalked spiderwort 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.