Cold hardiness & minimum temperature

Is Desert Rose (Adenium obesum)cold hardy? Hardiness zone & min temp

Also called Desert rose, Sabi star, Kudu, Mock azalea, Impala lily.

More about desert rose

About Desert Rose

Adenium obesum · also called Desert rose, Sabi star · flowering

Desert rose is a slow-growing succulent shrub prized for its swollen caudex and showy pink-to-red trumpet flowers. It demands full sun, sharp-draining soil, and dry-down between waterings, staying warm above 50F. ASPCA lists it as toxic to cats, dogs, and horses, so keep it well out of reach.

Cold limit: USDA USDA zones 10b-12 (grow outdoors year-round only where frost-free; elsewhere keep as a container plant brought indoors for winter) (18-35C)

Watch for — Root and caudex rot: The most common and serious problem, caused by overwatering or poor drainage, especially during winter dormancy. The caudex turns soft and mushy. Use gritty soil, a pot with drainage holes, and let soil dry between waterings.

What desert rose's hardiness rating actually means

Desert Rose 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 zones 10b-12 (grow outdoors year-round only where frost-free; elsewhere keep as a container plant brought indoors for winter) — 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). Desert Rose has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for desert rose 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 desert rose 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 desert rose can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Desert Rose hardiness — frequently asked questions

Is desert rose cold hardy?

Desert Rose 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. Desert Rose can only live outside year-round in genuinely frost-free climates (roughly USDA USDA zones 10b-12 (grow outdoors year-round only where frost-free; elsewhere keep as a container plant brought indoors for winter)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature desert rose can survive?

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Desert Rose has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is desert rose?

Desert Rose is rated USDA USDA zones 10b-12 (grow outdoors year-round only where frost-free; elsewhere keep as a container plant brought indoors for winter) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can desert rose 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 desert rose 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.