Cold hardiness & minimum temperature

Is Coral Bark Maple (Acer palmatum 'Sango-kaku')cold hardy? Hardiness zone & min temp

Also called Coral Bark Japanese Maple, Sango Kaku Maple.

More about coral bark maple

About Coral Bark Maple

Acer palmatum 'Sango-kaku' · also called Coral Bark Japanese Maple, Sango Kaku Maple · flowering

Coral Bark Maple is a spectacular Japanese maple cultivar grown primarily for its vivid coral-red young stems, which glow in winter sunlight when leaves have fallen. Spring leaves emerge bright yellow-green, turning soft gold in autumn. A year-round ornamental for borders and containers. Not toxic to pets.

Cold limit: USDA 5–8 · RHS H6 (−20 to 30°C)

Watch for — Late frost damage: Emerging spring foliage is frost-sensitive; protect with fleece if late frost threatens after bud-break.

What coral bark maple's hardiness rating actually means

Yes — coral bark maple is genuinely cold hardy. Rated RHS H6 and USDA 5–8, 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 5–8 — 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. Coral Bark Maple is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for coral bark maple 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 coral bark maple go outside or overwinter — and where?

Plant it out within USDA 5–8 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 coral bark maple can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Coral Bark Maple hardiness — frequently asked questions

Is coral bark maple cold hardy?

Yes — coral bark maple is genuinely cold hardy. Rated RHS H6 and USDA 5–8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Coral Bark Maple is hardy across USDA 5–8; 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 coral bark maple can survive?

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

What hardiness zone is coral bark maple?

Coral Bark Maple is rated USDA 5–8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can coral bark maple survive winter outside?

Plant it out within USDA 5–8 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 coral bark maple 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.