Cold hardiness & minimum temperature

Is Aeonium Decorum (Aeonium decorum)cold hardy? Hardiness zone & min temp

Also called green aeonium, chef's aeonium.

More about aeonium decorum

About Aeonium Decorum

Aeonium decorum · also called green aeonium, chef's aeonium · houseplant

Aeonium decorum is a bushy, freely branching aeonium from El Hierro, forming many small rosettes of green leaves edged in copper-pink on slim woody stems. It makes a dense, shrubby specimen and colours up well in bright light. Like its relatives it grows in cool months, rests in summer heat and demands very sharp drainage to avoid rot.

Cold limit: USDA 9-11 (indoor or container in colder US zones) · RHS H2 (10-27°C)

Watch for — Root and stem rot: Overwatering or heavy soil leads to mushy, dark stems. Remove affected tissue, let cuttings callus and replant in dry, fast-draining mix; keep it on the dry side in winter.

What aeonium decorum's hardiness rating actually means

Aeonium Decorum is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 9-11 (indoor or container in colder US zones) — 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 1 to 5 °C — tolerates cold but no real frost. Aeonium Decorum shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for aeonium decorum as it gets too cold:

Down to roughly about 1 to 5 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can aeonium decorum go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (indoor or container in colder US zones) or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

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 aeonium decorum can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline aeonium decorum

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

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Aeonium Decorum hardiness — frequently asked questions

Is aeonium decorum cold hardy?

Aeonium Decorum is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 9-11 (indoor or container in colder US zones) (and sheltered UK gardens) aeonium decorum can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature aeonium decorum can survive?

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Aeonium Decorum shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is aeonium decorum?

Aeonium Decorum is rated USDA 9-11 (indoor or container in colder US zones) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can aeonium decorum survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (indoor or container in colder US zones) or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect aeonium decorum from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.