Cold hardiness & minimum temperature

Is Hoya Pubicalyx 'Splash' (Hoya pubicalyx 'Splash')cold hardy? Hardiness zone & min temp

Also called Splash Wax Plant.

More about hoya pubicalyx 'splash'

About Hoya Pubicalyx 'Splash'

Hoya pubicalyx 'Splash' · also called Splash Wax Plant · houseplant

Hoya pubicalyx 'Splash' is a fast, vigorous climbing wax plant prized for its silvery flecked foliage and clusters of fragrant star-shaped flowers. It thrives in bright indirect light, dries between waterings, and rewards a slightly pot-bound root system. Easy and forgiving, it is an ideal first hoya for trellises or hanging baskets.

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

What hoya pubicalyx 'splash''s hardiness rating actually means

Hoya Pubicalyx 'Splash' 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 Pubicalyx 'Splash' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Hoya Pubicalyx 'Splash' hardiness — frequently asked questions

Is hoya pubicalyx 'splash' cold hardy?

Hoya Pubicalyx 'Splash' 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 Pubicalyx 'Splash' 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 pubicalyx 'splash' can survive?

What hardiness zone is hoya pubicalyx 'splash'?

Hoya Pubicalyx 'Splash' 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 pubicalyx 'splash' 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 pubicalyx 'splash' 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.