Cold hardiness & minimum temperature

Is Hybrid trumpet vine (Campsis x tagliabuana)cold hardy? Hardiness zone & min temp

Also called Hybrid trumpet vine, Trumpet creeper, Madame Galen trumpet vine.

More about hybrid trumpet vine

About Hybrid trumpet vine

Campsis x tagliabuana · also called Hybrid trumpet vine, Trumpet creeper · flowering

Hybrid trumpet vine (Campsis radicans × C. grandiflora) is a powerful, woody, deciduous climber bearing large salmon-red to orange trumpet flowers beloved by hummingbirds throughout summer and into autumn. Hardy in USDA zones 4–9, it needs a warm, sunny wall and annual pruning to stay manageable. All parts may cause mild skin irritation.

Cold limit: USDA 4-9 · RHS H5 (-20–35°C)

What hybrid trumpet vine's hardiness rating actually means

Yes — hybrid trumpet vine is genuinely cold hardy. Rated RHS H5 and USDA 4-9, 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 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 −15 to −10 °C. Hybrid trumpet vine is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for hybrid trumpet vine 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 hybrid trumpet vine 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 hybrid trumpet vine can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Hybrid trumpet vine hardiness — frequently asked questions

Is hybrid trumpet vine cold hardy?

Yes — hybrid trumpet vine is genuinely cold hardy. Rated RHS H5 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Hybrid trumpet vine 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 hybrid trumpet vine can survive?

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

What hardiness zone is hybrid trumpet vine?

Hybrid trumpet vine is rated USDA 4-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can hybrid trumpet vine 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 hybrid trumpet vine 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.