Cold hardiness & minimum temperature

Is Hoya 'Mathilde' (Hoya carnosa × serpens 'Mathilde')cold hardy? Hardiness zone & min temp

Also called Hoya Mathilde, Mathilde wax plant, Mathilde hoya, wax plant 'Mathilde'.

More about hoya 'mathilde'

About Hoya 'Mathilde'

Hoya carnosa × serpens 'Mathilde' · also called Hoya Mathilde, Mathilde wax plant · houseplant

Hoya 'Mathilde' is a compact trailing wax-plant hybrid (Hoya carnosa × serpens) prized for small, silver-flecked leaves and fragrant pink star-shaped blooms. Give it bright indirect light, a chunky free-draining mix, and let the soil mostly dry between waterings. The genus is ASPCA-listed non-toxic, so it is considered pet-safe.

Cold limit: USDA 10-12 (grown as an indoor houseplant in cooler zones; not frost hardy) (16-27°C)

Watch for — Not blooming: Usually too little light or a too-young plant. Give brighter indirect light, keep it slightly root-bound, and allow a cooler, drier winter rest to trigger flowering. Never cut off the bare peduncles (spurs) — they rebloom.

What hoya 'mathilde''s hardiness rating actually means

Hoya 'Mathilde' 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 10-12 (grown as an indoor houseplant in cooler zones; not frost hardy) — 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). Hoya 'Mathilde' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for hoya 'mathilde' 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 hoya 'mathilde' 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 hoya 'mathilde' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Hoya 'Mathilde' hardiness — frequently asked questions

Is hoya 'mathilde' cold hardy?

Hoya 'Mathilde' 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 'Mathilde' can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (grown as an indoor houseplant in cooler zones; not frost hardy)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature hoya 'mathilde' can survive?

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

What hardiness zone is hoya 'mathilde'?

Hoya 'Mathilde' is rated USDA 10-12 (grown as an indoor houseplant in cooler zones; not frost hardy) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can hoya 'mathilde' 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 hoya 'mathilde' 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.