Cold hardiness & minimum temperature

Is Greengage (Prunus domestica 'Reine Claude Dorée')cold hardy? Hardiness zone & min temp

Also called greengage, Reine Claude, green plum.

More about greengage

About Greengage

Prunus domestica 'Reine Claude Dorée' · also called greengage, Reine Claude · edible

The greengage is a connoisseur's dessert plum bearing small, round, green-to-gold fruit with exceptionally rich, honeyed flesh. The original Reine Claude is only partially self-fertile and needs warmth and a sheltered, sunny wall to ripen well, rewarding patient gardeners in good summers with arguably the finest-flavoured plum of all.

Cold limit: USDA 5-9 (outdoor; wall-trained in cooler areas) · RHS H6 (-18 to 30°C)

Watch for — Shy or erratic cropping: Cold sites and poor pollination give light crops; grow against a warm wall and plant a compatible pollinator like Victoria nearby to improve fruit set.

What greengage's hardiness rating actually means

Yes — greengage is genuinely cold hardy. Rated RHS H6 and USDA 5-9 (outdoor; wall-trained in cooler areas), 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 5-9 (outdoor; wall-trained in cooler areas) — 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. Greengage is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for greengage 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 greengage go outside or overwinter — and where?

Plant it out within USDA 5-9 (outdoor; wall-trained in cooler areas) 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 greengage can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Greengage hardiness — frequently asked questions

Is greengage cold hardy?

Yes — greengage is genuinely cold hardy. Rated RHS H6 and USDA 5-9 (outdoor; wall-trained in cooler areas), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Greengage is hardy across USDA 5-9 (outdoor; wall-trained in cooler areas); 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 greengage can survive?

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

What hardiness zone is greengage?

Greengage is rated USDA 5-9 (outdoor; wall-trained in cooler areas) and RHS H6 — Hardy throughout the UK and northern Europe.

Can greengage survive winter outside?

Plant it out within USDA 5-9 (outdoor; wall-trained in cooler areas) 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 greengage 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.