Cold hardiness & minimum temperature

Is Bosc pear (Pyrus communis 'Beurré Bosc')cold hardy? Hardiness zone & min temp

Also called Bosc pear, Beurré Bosc, Kaiser Alexander.

More about bosc pear

About Bosc pear

Pyrus communis 'Beurré Bosc' · also called Bosc pear, Beurré Bosc · edible

Beurré Bosc is a classic mid-to-late season dessert and culinary pear with distinctive russet skin, a long elegant neck, and firm, sweet, spiced flesh that holds its shape when cooked. It requires a pollination partner and performs best in full sun with warm summers to ripen fully. A reliable cropper on fertile soils.

Cold limit: USDA 5-9 · RHS H6 (-20°C to 35°C)

Watch for — Fireblight (Erwinia amylovora): Beurré Bosc is relatively susceptible to fireblight. Wilted, blackened shoot tips resemble frost damage. Prune well below the infection, sterilise tools with disinfectant between cuts, and avoid excess nitrogen fertiliser.

What bosc pear's hardiness rating actually means

Yes — bosc pear is genuinely cold hardy. Rated RHS H6 and USDA 5-9, 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 5-9 — 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. Bosc pear is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for bosc pear 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 bosc pear go outside or overwinter — and where?

Plant it out within USDA 5-9 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 bosc pear can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Bosc pear hardiness — frequently asked questions

Is bosc pear cold hardy?

Yes — bosc pear is genuinely cold hardy. Rated RHS H6 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Bosc pear is hardy across USDA 5-9; 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 bosc pear can survive?

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

What hardiness zone is bosc pear?

Bosc pear is rated USDA 5-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can bosc pear survive winter outside?

Plant it out within USDA 5-9 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 bosc pear 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.