Cold hardiness & minimum temperature

Is Hoya Cagayanensis (Hoya cagayanensis)cold hardy? Hardiness zone & min temp

Also called Cagayan hoya.

More about hoya cagayanensis

About Hoya Cagayanensis

Hoya cagayanensis · also called Cagayan hoya · houseplant

Hoya cagayanensis is a Philippine epiphytic climber with broad, glossy, deeply veined green leaves on flexible vining stems. It bears rounded clusters of waxy, pale cream to yellowish fragrant flowers. A vigorous, leafy hoya that climbs well on support and thrives with bright indirect light, warmth, and a chunky, free-draining epiphytic mix.

Cold limit: USDA 10-12 (grown indoors in most US homes) · RHS H1b (18-29°C)

Watch for — Root rot in dense soil: Standard potting compost stays too wet for these epiphytic roots. Use a chunky bark-based mix with sharp drainage and reduce watering in winter to keep the root system healthy.

What hoya cagayanensis's hardiness rating actually means

Hoya Cagayanensis 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 10-12 (grown indoors 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 10 °C (sustained cold below this is damaging). Hoya Cagayanensis has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Hoya Cagayanensis hardiness — frequently asked questions

Is hoya cagayanensis cold hardy?

Hoya Cagayanensis 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. Hoya Cagayanensis can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (grown indoors in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature hoya cagayanensis can survive?

What hardiness zone is hoya cagayanensis?

Hoya Cagayanensis is rated USDA 10-12 (grown indoors in most US homes) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can hoya cagayanensis 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 hoya cagayanensis 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.