UK hardiness
Is Heuchera 'Plum Pudding' hardy in the UK?
Heuchera 'Plum Pudding'
More about heuchera 'plum pudding' in the UK
Heuchera 'Plum Pudding' and the RHS hardiness rating
Heuchera 'Plum Pudding' is rated RHS H5 — hardy in a cold winter, meaning it withstands winter minimums of about -15 to -10°C. In practice that means it hardy through most of the UK even in severe winters. The RHS rating describes an absolute minimum temperature, not an average: a single hard frost below its band is what does the damage, so the question is always "what is the coldest night my garden gets?", not "what is a typical winter here?".
This follows the RHS plant hardiness rating system (H1a–H7), the UK standard. For the US growing-zone view, see the heuchera 'plum pudding' USDA hardiness guide.
Does UK region change it?
UK winters vary far more by locality than by latitude. Mild western and coastal areas (the south-west, Pembrokeshire, western Scotland's coast) and urban heat islands run several degrees warmer than inland frost pockets, valleys, and exposed eastern sites at the same latitude. A plant marginal on its RHS rating often survives in a sheltered town garden but fails 20 miles inland — so judge by your own coldest recorded night and microclimate (a south-facing wall, a courtyard) rather than the regional average.
Overwintering heuchera 'plum pudding' in the UK
For a borderline-hardy plant, the UK winter killers are not just cold air but cold wet roots and wind. Improve drainage before winter, mulch the root zone, move containers to a sheltered spot or against a warm wall, and use horticultural fleece on hard-frost nights. Established plants in free-draining soil take far more cold than a recently planted one in heavy, wet ground.
Heuchera 'Plum Pudding' UK hardiness — frequently asked questions
Is heuchera 'plum pudding' hardy in the UK?
Heuchera 'Plum Pudding' is rated RHS H5 (hardy in a cold winter, hardy to about -15 to -10°C). It hardy through most of the UK even in severe winters.
Can heuchera 'plum pudding' stay outside over winter in the UK?
In most of the UK, yes, if your garden's coldest night stays within its RHS H5 band (around -15 to -10°C). In colder inland or northern gardens, give it a sheltered spot, sharp drainage, and fleece on hard-frost nights.
What does RHS H5 mean?
RHS hardiness ratings run H1a (needs a heated glasshouse) to H7 (survives below -20°C). Heuchera 'Plum Pudding''s rating, H5, means hardy in a cold winter — it tolerates winter minimums of about -15 to -10°C. The rating is an absolute minimum, not an average.
How do I overwinter heuchera 'plum pudding' in the UK?
For a borderline-hardy plant, the UK winter killers are not just cold air but cold wet roots and wind. Improve drainage before winter, mulch the root zone, move containers to a sheltered spot or against a warm wall, and use horticultural fleece on hard-frost nights. Established plants in free-draining soil take far more cold than a recently planted one in heavy, wet ground.
Does UK region change whether heuchera 'plum pudding' survives?
UK winters vary far more by locality than by latitude. Mild western and coastal areas (the south-west, Pembrokeshire, western Scotland's coast) and urban heat islands run several degrees warmer than inland frost pockets, valleys, and exposed eastern sites at the same latitude. A plant marginal on its RHS rating often survives in a sheltered town garden but fails 20 miles inland — so judge by your own coldest recorded night and microclimate (a south-facing wall, a courtyard) rather than the regional average.
More heuchera 'plum pudding' care
See the full heuchera 'plum pudding' care guide, its temperature & humidity needs, and the US (USDA) hardiness version of this page.