Cold hardiness & minimum temperature

Is Hindu rope plant (Hoya carnosa 'Compacta')cold hardy? Hardiness zone & min temp

Also called Hindu rope plant, krinkle kurl, wax plant, porcelain flower.

More about hindu rope plant

About Hindu rope plant

Hoya carnosa 'Compacta' · also called Hindu rope plant, krinkle kurl · houseplant

The Hindu rope plant is a slow-growing, semi-succulent Hoya cultivar with curled, waxy leaves that trail in dense ropes and produce clusters of fragrant, star-shaped flowers. It thrives in bright indirect light and resents overwatering. The ASPCA lists it (as wax plant) non-toxic to cats and dogs.

Cold limit: USDA 10-11 (indoor-only in most US homes) (16-27°C)

Watch for — Yellowing leaves / root rot: Overwatering or cold draughts; let the soil dry out and improve drainage. Mushy roots mean root rot from staying wet.

What hindu rope plant's hardiness rating actually means

Hindu rope plant 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 10-11 (indoor-only in most US homes) — 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 5 °C (and never frost). Hindu rope plant has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for hindu rope plant as it gets too cold:

Below about about 5 °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 hindu rope plant go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °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 hindu rope plant can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Hindu rope plant hardiness — frequently asked questions

Is hindu rope plant cold hardy?

Hindu rope plant 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. Hindu rope plant can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor-only in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature hindu rope plant can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Hindu rope plant has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is hindu rope plant?

Hindu rope plant is rated USDA 10-11 (indoor-only in most US homes) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can hindu rope plant survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °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 hindu rope plant below its minimum temperature?

Below about about 5 °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.