Cold hardiness & minimum temperature

Is Turkish Hazel (Corylus colurna)cold hardy? Hardiness zone & min temp

Also called Turkish hazel, Turkish filbert, tree hazel.

More about turkish hazel

About Turkish Hazel

Corylus colurna · also called Turkish hazel, Turkish filbert · edible

Turkish hazel is a large, single-trunked tree hazel with a strikingly symmetrical pyramidal crown and corky, flaking bark. Unusually for the genus it grows as a true tree rather than a suckering bush, making it a tough urban street and specimen tree. It bears small, thick-shelled edible nuts and tolerates heat, drought, and poor soil.

Cold limit: USDA 4-7 (outdoor temperate tree) · RHS H7 (-30 to 35°C)

What turkish hazel's hardiness rating actually means

Yes — turkish hazel is genuinely cold hardy. Rated RHS H7 and USDA 4-7 (outdoor temperate tree), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 4-7 (outdoor temperate tree) — 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 below about −20 °C. Turkish Hazel is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for turkish hazel as it gets too cold:

It tolerates winter lows to about −20 °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 turkish hazel go outside or overwinter — and where?

Plant it out within USDA 4-7 (outdoor temperate tree) 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 turkish hazel can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Turkish Hazel hardiness — frequently asked questions

Is turkish hazel cold hardy?

Yes — turkish hazel is genuinely cold hardy. Rated RHS H7 and USDA 4-7 (outdoor temperate tree), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Turkish Hazel is hardy across USDA 4-7 (outdoor temperate tree); 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 turkish hazel can survive?

Minimum survivable temperature is roughly below about −20 °C. Turkish Hazel is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is turkish hazel?

Turkish Hazel is rated USDA 4-7 (outdoor temperate tree) and RHS H7 — Hardy in the severest European continental winters.

Can turkish hazel survive winter outside?

Plant it out within USDA 4-7 (outdoor temperate tree) 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 turkish hazel below its minimum temperature?

It tolerates winter lows to about −20 °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.