Cold hardiness & minimum temperature

Is Five-Nerved Wax Plant (Hoya quinquenervia)cold hardy? Hardiness zone & min temp

Also called Five-nerved wax plant, Five-veined hoya, Quinquenervia hoya.

More about five-nerved wax plant

About Five-Nerved Wax Plant

Hoya quinquenervia · also called Five-nerved wax plant, Five-veined hoya · houseplant

Hoya quinquenervia is a striking Southeast Asian epiphytic vine named for the five prominent veins that run the length of its broad, leathery leaves, creating a distinctive textural pattern. It produces clusters of small, fragrant, star-shaped flowers from persistent peduncles and is a favourite among hoya collectors for its unusual, architecturally veined foliage. Care follows standard hoya principles: bright indirect light, a free-draining epiphytic mix, and watering only when the medium has partially dried. It is regarded as non-toxic to cats and dogs, consistent with ASPCA guidance for the Hoya genus.

Cold limit: USDA 11-12 (indoor in most climates) · RHS H1b (18-30°C)

Watch for — Yellow lower leaves: Lower leaf yellowing usually indicates overwatering or cold draughts. Let the medium dry more between waterings, check drainage, and ensure the plant is not positioned near a door or vent bringing cold air.

What five-nerved wax plant's hardiness rating actually means

Five-Nerved Wax 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 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 11-12 (indoor in most climates) — 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). Five-Nerved Wax Plant has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for five-nerved wax plant 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 five-nerved wax plant 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 five-nerved wax plant can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Five-Nerved Wax Plant hardiness — frequently asked questions

Is five-nerved wax plant cold hardy?

Five-Nerved Wax 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. Five-Nerved Wax Plant can only live outside year-round in genuinely frost-free climates (roughly USDA 11-12 (indoor in most climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature five-nerved wax plant can survive?

What hardiness zone is five-nerved wax plant?

Five-Nerved Wax Plant is rated USDA 11-12 (indoor in most climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can five-nerved wax plant 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 five-nerved wax plant 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.