Cold hardiness & minimum temperature

Is Shingle Plant Hoya (Hoya imbricata)cold hardy? Hardiness zone & min temp

Also called Shingle plant hoya, Shingling hoya, Bowl-leaf hoya, Ant-plant hoya, Imbricate wax plant.

More about shingle plant hoya

About Shingle Plant Hoya

Hoya imbricata · also called Shingle plant hoya, Shingling hoya · tropical

Hoya imbricata is an unusual epiphytic wax plant from the Philippines and Sulawesi that presses single, dome-shaped leaves flat against bark like roof tiles, sheltering ant colonies in the wild. Give it bright indirect light, high humidity and a very dry-out-between-waterings rhythm. The ASPCA lists the Hoya genus as non-toxic, so it is pet-safe.

Cold limit: USDA 10b-12 (outdoors only in frost-free tropical climates; grown as a houseplant elsewhere) (18-29°C)

Watch for — Root rot from overwatering: The single most common cause of decline. This epiphyte resents a soggy, dense mix; yellowing, mushy leaves and blackened roots are the warning signs. Let the mix dry out almost fully, use a chunky free-draining medium and a pot with drainage holes, and ease right off in winter.

What shingle plant hoya's hardiness rating actually means

Shingle Plant Hoya 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 10b-12 (outdoors only in frost-free tropical climates; grown as a houseplant elsewhere) — 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). Shingle Plant Hoya has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Shingle Plant Hoya hardiness — frequently asked questions

Is shingle plant hoya cold hardy?

Shingle Plant Hoya 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. Shingle Plant Hoya can only live outside year-round in genuinely frost-free climates (roughly USDA 10b-12 (outdoors only in frost-free tropical climates; grown as a houseplant elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature shingle plant hoya can survive?

What hardiness zone is shingle plant hoya?

Shingle Plant Hoya is rated USDA 10b-12 (outdoors only in frost-free tropical climates; grown as a houseplant elsewhere) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can shingle plant hoya 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 shingle plant hoya 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.