Cold hardiness & minimum temperature

Is Ohio Spiderwort (Tradescantia ohiensis)cold hardy? Hardiness zone & min temp

Also called Ohio Spiderwort, Smooth Spiderwort, Blue Jacket.

More about ohio spiderwort

About Ohio Spiderwort

Tradescantia ohiensis · also called Ohio Spiderwort, Smooth Spiderwort · flowering

Tradescantia ohiensis is a vigorous, upright native perennial of prairies, roadsides, and open woodlands across the central and eastern United States, producing bright blue-violet three-petalled flowers on smooth, glaucous stems from late spring into early summer. It is exceptionally adaptable, tolerating clay, sand, drought, and poor soils once established. The most important care tip is to cut stems back by half in midsummer after flowering to prevent floppy, untidy growth and encourage a flush of fresh foliage and occasional autumn rebloom. Although T. ohiensis is not individually listed as toxic by the ASPCA, a related species (T. fluminensis) is listed as causing dermatitis in cats, dogs, and horses, so handle with care.

Cold limit: USDA 4-9 · RHS H6 (-30°C to 38°C)

What ohio spiderwort's hardiness rating actually means

Yes — ohio 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. Ohio Spiderwort is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for ohio 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 ohio 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 ohio spiderwort can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Ohio Spiderwort hardiness — frequently asked questions

Is ohio spiderwort cold hardy?

Yes — ohio 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. Ohio 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 ohio spiderwort can survive?

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

What hardiness zone is ohio spiderwort?

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

Can ohio 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 ohio 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.