Cold hardiness & minimum temperature

Is Stern's medlar (Mespilus canescens)cold hardy? Hardiness zone & min temp

Also called Stern's medlar, hoary medlar.

More about stern's medlar

About Stern's medlar

Mespilus canescens · also called Stern's medlar, hoary medlar · edible

A critically rare North American native (known from a single site in eastern Arkansas), Stern's medlar is a multi-stemmed deciduous shrub or small tree in the rose family. It bears white spring flowers and small, glossy deep-red pomes edible when bletted. Suited to USDA zones 6–8, it prefers moist, fertile, well-drained soil in sun to part shade.

Cold limit: USDA 6-8 · RHS H5 (-15 to 35°C)

What stern's medlar's hardiness rating actually means

Yes — stern's medlar is genuinely cold hardy. Rated RHS H5 and USDA 6-8, 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 6-8 — 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. Stern's medlar is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for stern's medlar 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 stern's medlar go outside or overwinter — and where?

Plant it out within USDA 6-8 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 stern's medlar can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Stern's medlar hardiness — frequently asked questions

Is stern's medlar cold hardy?

Yes — stern's medlar is genuinely cold hardy. Rated RHS H5 and USDA 6-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Stern's medlar is hardy across USDA 6-8; 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 stern's medlar can survive?

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

What hardiness zone is stern's medlar?

Stern's medlar is rated USDA 6-8 and RHS H5 — Hardy in most of the UK and in cold winters.

Can stern's medlar survive winter outside?

Plant it out within USDA 6-8 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 stern's medlar 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.