Cold hardiness & minimum temperature

Is Crossvine (Bignonia capreolata)cold hardy? Hardiness zone & min temp

Also called Crossvine, Trumpet Flower, Quarantine Vine.

More about crossvine

About Crossvine

Bignonia capreolata · also called Crossvine, Trumpet Flower · flowering

Crossvine is a native North American woody vine with tendril-like clinging holdfasts, producing striking reddish-orange and yellow tubular flowers beloved by hummingbirds in spring. Semi-evergreen and adaptable, it tolerates a wide range of soils and is hardy across much of the South and Midwest. Excellent on fences, walls, and pergolas.

Cold limit: USDA 5-9 · RHS H5 (-20–38°C)

Watch for — Sparse spring flowering: Flowers form on previous year's wood. If the vine is pruned in late winter or early spring, the flower buds are removed. Prune only immediately after flowering ends in late spring or early summer.

What crossvine's hardiness rating actually means

Yes — crossvine is genuinely cold hardy. Rated RHS H5 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 5-9 — 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 −15 to −10 °C. Crossvine is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for crossvine as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 crossvine go outside or overwinter — and where?

Plant it out within USDA 5-9 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 crossvine can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Crossvine hardiness — frequently asked questions

Is crossvine cold hardy?

Yes — crossvine is genuinely cold hardy. Rated RHS H5 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Crossvine is hardy across USDA 5-9; 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 crossvine can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Crossvine is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is crossvine?

Crossvine is rated USDA 5-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can crossvine survive winter outside?

Plant it out within USDA 5-9 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 crossvine below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.