Cold hardiness & minimum temperature

Is Impala Lily (Adenium multiflorum)cold hardy? Hardiness zone & min temp

Also called Impala Lily, Sabi Star, Desert Rose, Mock Azalea.

More about impala lily

About Impala Lily

Adenium multiflorum · also called Impala Lily, Sabi Star · tropical

Impala Lily is a spectacular deciduous succulent from southern Africa that bears masses of boldly bicoloured white and red trumpet flowers on bare branches during its long winter dormancy. Prized as a garden specimen in USDA zones 10–11 and as a container plant elsewhere, it demands excellent drainage, full sun, and a dry, cool dormancy period. All parts are toxic, with traditional use as fish and arrow poison.

Cold limit: USDA 10b-11 · RHS H1b (18–35°C)

Watch for — Root rot during dormancy: The most common cause of death in cultivation. During the obligatory autumn-winter dormancy, the plant is leafless and any soil moisture leads to rapid caudex rot. Keep the plant completely dry from leaf fall until new growth emerges in late winter. If soft, dark tissue appears on the caudex, cut it out immediately, dust with sulphur, and allow to dry.

What impala lily's hardiness rating actually means

Impala Lily 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 10b-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 10 °C (sustained cold below this is damaging). Impala Lily has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Impala Lily hardiness — frequently asked questions

Is impala lily cold hardy?

Impala Lily 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. Impala Lily can only live outside year-round in genuinely frost-free climates (roughly USDA 10b-11); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature impala lily can survive?

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

What hardiness zone is impala lily?

Impala Lily is rated USDA 10b-11 and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can impala lily 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 impala lily 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.