Cold hardiness & minimum temperature

Is Spotted Aichryson (Aichryson punctatum)cold hardy? Hardiness zone & min temp

Also called Spotted Aichryson.

More about spotted aichryson

About Spotted Aichryson

Aichryson punctatum · also called Spotted Aichryson · houseplant

Aichryson punctatum is a small succulent shrublet from the Canary Islands distinguished by its subtly spotted or dotted leaf markings. It forms compact, branching stems with hairy, fleshy leaves and produces yellow flowers in spring. Grow in a bright spot with gritty, free-draining compost and restrained watering for best results as a windowsill collector's plant.

Cold limit: USDA 10-11 · RHS H2 (8–24°C)

What spotted aichryson's hardiness rating actually means

Spotted Aichryson 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 10-11 — 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. Spotted Aichryson shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for spotted aichryson 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 spotted aichryson go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 10-11 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 spotted aichryson 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 spotted aichryson

Spotted Aichryson 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.

Spotted Aichryson hardiness — frequently asked questions

Is spotted aichryson cold hardy?

Spotted Aichryson 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 10-11 (and sheltered UK gardens) spotted aichryson can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature spotted aichryson can survive?

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

What hardiness zone is spotted aichryson?

Spotted Aichryson is rated USDA 10-11 and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can spotted aichryson survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 10-11 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 spotted aichryson 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.