Cold hardiness & minimum temperature

Is Five-leaf akebia (Akebia x pentaphylla)cold hardy? Hardiness zone & min temp

Also called Five-leaf akebia, Chocolate vine.

More about five-leaf akebia

About Five-leaf akebia

Akebia x pentaphylla · also called Five-leaf akebia, Chocolate vine · flowering

Five-leaf akebia is a vigorous, semi-evergreen twining climber — a natural hybrid of Akebia quinata and A. trifoliata — bearing racemes of lightly vanilla-scented reddish-purple flowers in spring. It adapts to sun or shade in almost any well-drained soil and is very hardy. Rarely fruits without cross-pollination. Toxicity is not established.

Cold limit: USDA 5-9 · RHS H5 (-15–25°C)

Watch for — Frost damage to flowers: Early-spring flowers can be damaged by late frosts, especially on east-facing walls where rapid thawing causes cell damage. Choose a sheltered south- or west-facing aspect in frost-prone gardens.

What five-leaf akebia's hardiness rating actually means

Yes — five-leaf akebia 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. Five-leaf akebia is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for five-leaf akebia 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 five-leaf akebia 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 five-leaf akebia can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Five-leaf akebia hardiness — frequently asked questions

Is five-leaf akebia cold hardy?

Yes — five-leaf akebia 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. Five-leaf akebia 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 five-leaf akebia can survive?

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

What hardiness zone is five-leaf akebia?

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

Can five-leaf akebia 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 five-leaf akebia 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.