Cold hardiness & minimum temperature

Is Plum Pudding Heuchera (Heuchera 'Plum Pudding')cold hardy? Hardiness zone & min temp

Also called Plum Pudding coral bells, silvered purple heuchera.

More about plum pudding heuchera

About Plum Pudding Heuchera

Heuchera 'Plum Pudding' · also called Plum Pudding coral bells, silvered purple heuchera · flowering

'Plum Pudding' is a popular coral bells with metallic plum-purple maple-shaped leaves overlaid with a silvery sheen and darker veins, holding colour through the season and into mild winters. A reliable evergreen mound, it sends up slender stems of tiny creamy flowers in early summer. A versatile, well-behaved choice for shade borders, edging, and containers.

Cold limit: USDA 4-9 · RHS H6 (-34 to 30°C)

Watch for — Crown heaving: Winter freeze-thaw pushes the woody crown out of the ground, exposing roots. Mulch in autumn and replant or firm heaved crowns in spring.

What plum pudding heuchera's hardiness rating actually means

Yes — plum pudding heuchera is genuinely cold hardy. Rated RHS H6 and USDA 4-9, 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 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 −20 to −15 °C. Plum Pudding Heuchera is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for plum pudding heuchera 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 plum pudding heuchera 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 plum pudding heuchera can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Plum Pudding Heuchera hardiness — frequently asked questions

Is plum pudding heuchera cold hardy?

Yes — plum pudding heuchera is genuinely cold hardy. Rated RHS H6 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Plum Pudding Heuchera 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 plum pudding heuchera can survive?

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

What hardiness zone is plum pudding heuchera?

Plum Pudding Heuchera is rated USDA 4-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can plum pudding heuchera 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 plum pudding heuchera 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.