UK hardiness
Is Choy Sum 'Green Lance' hardy in the UK?
Brassica rapa var. parachinensis 'Green Lance'
More about choy sum 'green lance' in the UK
Choy Sum 'Green Lance' and the RHS hardiness rating
Choy Sum 'Green Lance' is rated RHS H3 (tolerates light frost; tender to hard freezes) — half-hardy, meaning it withstands winter minimums of about -5 to 1°C. In practice that means it survives outdoors only in mild or coastal areas, ideally with winter protection (fleece, a sheltered wall). 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 choy sum 'green lance' 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 choy sum 'green lance' 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.
Choy Sum 'Green Lance' UK hardiness — frequently asked questions
Is choy sum 'green lance' hardy in the UK?
Choy Sum 'Green Lance' is rated RHS H3 (tolerates light frost; tender to hard freezes) (half-hardy, hardy to about -5 to 1°C). It survives outdoors only in mild or coastal areas, ideally with winter protection (fleece, a sheltered wall).
Can choy sum 'green lance' stay outside over winter in the UK?
In most of the UK, yes, if your garden's coldest night stays within its RHS H3 (tolerates light frost; tender to hard freezes) band (around -5 to 1°C). In colder inland or northern gardens, give it a sheltered spot, sharp drainage, and fleece on hard-frost nights.
What does RHS H3 (tolerates light frost; tender to hard freezes) mean?
RHS hardiness ratings run H1a (needs a heated glasshouse) to H7 (survives below -20°C). Choy Sum 'Green Lance''s rating, H3 (tolerates light frost; tender to hard freezes), means half-hardy — it tolerates winter minimums of about -5 to 1°C. The rating is an absolute minimum, not an average.
How do I overwinter choy sum 'green lance' 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 choy sum 'green lance' 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 choy sum 'green lance' care
See the full choy sum 'green lance' care guide, its temperature & humidity needs, and the US (USDA) hardiness version of this page.