Cold hardiness & minimum temperature

Is Globe Artichoke (Cynara cardunculus var. scolymus 'Green Globe')cold hardy? Hardiness zone & min temp

Also called Green Globe artichoke, globe artichoke.

More about globe artichoke

About Globe Artichoke

Cynara cardunculus var. scolymus 'Green Globe' · also called Green Globe artichoke, globe artichoke · edible

The globe artichoke is a thistle-family perennial grown for its plump, edible flower buds harvested before they bloom. 'Green Globe' is the most widely grown open-pollinated cultivar, forming a large silvery-leaved clump. It needs full sun, deep rich soil and a long, frost-free growing season, and crops best from its second year onward.

Cold limit: USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7) · RHS H4 (13-24°C)

Watch for — Crown rot over winter: Cold, wet soil rots the crown. Improve drainage, plant on a slight ridge, and apply a dry mulch over the crown in winter in colder areas.

What globe artichoke's hardiness rating actually means

Yes — globe artichoke is genuinely cold hardy. Rated RHS H4 and USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7) — 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 −10 to −5 °C. Globe Artichoke is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for globe artichoke as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 globe artichoke go outside or overwinter — and where?

Plant it out within USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7) 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 globe artichoke can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Frost protection for borderline globe artichoke

Globe Artichoke is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

At the cold edge of its range, mulch the root zone in late autumn to buffer the deepest freezes.
Protect container specimens — pots freeze through far faster than open ground, costing roughly a zone of hardiness.
Shelter new growth from late spring frosts with fleece if a hard night is forecast.

Globe Artichoke hardiness — frequently asked questions

Is globe artichoke cold hardy?

Yes — globe artichoke is genuinely cold hardy. Rated RHS H4 and USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Globe Artichoke is hardy across USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7); 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 globe artichoke can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Globe Artichoke is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is globe artichoke?

Globe Artichoke is rated USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can globe artichoke survive winter outside?

Plant it out within USDA 7-11 (overwinters outdoors in mild zones; mulch or lift the crown in zone 7) 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.

How do I protect globe artichoke from frost?

At the cold edge of its range, mulch the root zone in late autumn to buffer the deepest freezes. Protect container specimens — pots freeze through far faster than open ground, costing roughly a zone of hardiness. Shelter new growth from late spring frosts with fleece if a hard night is forecast.