Cold hardiness & minimum temperature

Is Saphyr Rouge Firethorn (Pyracantha coccinea 'Saphyr Rouge')cold hardy? Hardiness zone & min temp

Also called Saphyr Rouge Firethorn, Red Firethorn, Scarlet Firethorn.

More about saphyr rouge firethorn

About Saphyr Rouge Firethorn

Pyracantha coccinea 'Saphyr Rouge' · also called Saphyr Rouge Firethorn, Red Firethorn · flowering

A vigorous, scab-resistant and fireblight-resistant evergreen Pyracantha bearing masses of white hawthorn-like flowers in late spring followed by an exceptionally heavy crop of brilliant red berries in autumn and winter. 'Saphyr Rouge' is widely used for wall training, hedging, and wildlife cover. Pyracantha berries are mildly toxic to pets.

Cold limit: USDA 6-9 · RHS H5 (-15 to 38°C)

What saphyr rouge firethorn's hardiness rating actually means

Yes — saphyr rouge firethorn is genuinely cold hardy. Rated RHS H5 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 6-9 — 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 −15 to −10 °C. Saphyr Rouge Firethorn is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for saphyr rouge firethorn as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 saphyr rouge firethorn go outside or overwinter — and where?

Plant it out within USDA 6-9 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 saphyr rouge firethorn can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Saphyr Rouge Firethorn hardiness — frequently asked questions

Is saphyr rouge firethorn cold hardy?

Yes — saphyr rouge firethorn is genuinely cold hardy. Rated RHS H5 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Saphyr Rouge Firethorn is hardy across USDA 6-9; 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 saphyr rouge firethorn can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Saphyr Rouge Firethorn is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is saphyr rouge firethorn?

Saphyr Rouge Firethorn is rated USDA 6-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can saphyr rouge firethorn survive winter outside?

Plant it out within USDA 6-9 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 saphyr rouge firethorn below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.