Cold hardiness & minimum temperature

Is Tree Houseleek (Aeonium arboreum)cold hardy? Hardiness zone & min temp

Also called Tree houseleek, Tree aeonium, Houseleek tree, Irish rose.

More about tree houseleek

About Tree Houseleek

Aeonium arboreum · also called Tree houseleek, Tree aeonium · houseplant

Tree houseleek (Aeonium arboreum) is a branching, frost-tender succulent from the Canary Islands, prized for glossy rosettes on woody stems. Give it bright direct light, gritty fast-draining soil, and water only when the soil dries. It grows in winter and rests in summer. Not ASPCA-listed, so treat as mildly toxic and check with a vet.

Cold limit: USDA USDA 9b-11 (RHS hardiness H1c; needs a minimum of about 5-10C / 41-50F and must be protected from frost) (10-24C ideal; tolerates 5-35C, frost-tender below about 2C)

Watch for — Frost damage: Even a light frost turns leaves mushy and translucent. Bring plants indoors or under glass before temperatures approach freezing.

What tree houseleek's hardiness rating actually means

Tree Houseleek is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Its RHS rating of H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA USDA 9b-11 (RHS hardiness H1c; needs a minimum of about 5-10C / 41-50F and must be protected from frost) — 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 °C (sustained cold below this is damaging). Tree Houseleek has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for tree houseleek as it gets too cold:

Below about about 10 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches.
A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover.
Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.

Can tree houseleek go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °C, in shade or dappled light, hardened off gradually.
Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C.
It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

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 tree houseleek can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Tree Houseleek hardiness — frequently asked questions

Is tree houseleek cold hardy?

Tree Houseleek is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Indoor-only in almost every home. Tree Houseleek can only live outside year-round in genuinely frost-free climates (roughly USDA USDA 9b-11 (RHS hardiness H1c; needs a minimum of about 5-10C / 41-50F and must be protected from frost)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature tree houseleek can survive?

What hardiness zone is tree houseleek?

Tree Houseleek is rated USDA USDA 9b-11 (RHS hardiness H1c; needs a minimum of about 5-10C / 41-50F and must be protected from frost) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can tree houseleek survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °C, in shade or dappled light, hardened off gradually. Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C. It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

What happens to tree houseleek below its minimum temperature?

Below about about 10 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches. A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover. Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.