Cold hardiness & minimum temperature

Is Anguloa clowesii (Anguloa clowesii)cold hardy? Hardiness zone & min temp

Also called Cradle Orchid, Tulip Orchid.

More about anguloa clowesii

About Anguloa clowesii

Anguloa clowesii · also called Cradle Orchid, Tulip Orchid · flowering

Anguloa clowesii, the cradle or tulip orchid, is a cool-growing Colombian species famous for cupped, waxy lemon-yellow spring flowers with a loose, rocking lip that gives it its name. Closely related to Lycaste, it forms large pseudobulbs and broad pleated deciduous leaves, and needs bright light, generous summer water, and a cooler winter rest to bloom.

Cold limit: USDA 10-11 (grown indoors / greenhouse in most US and UK homes) · RHS H1b (10-24°C)

Watch for — Failure to bloom: Most often from too-warm winters or skipping the rest. A cooler, somewhat drier winter period is needed to set the spring flower stalks from mature growths.

What anguloa clowesii's hardiness rating actually means

Anguloa clowesii 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 10-11 (grown indoors / greenhouse in most US and UK 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). Anguloa clowesii has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Anguloa clowesii hardiness — frequently asked questions

Is anguloa clowesii cold hardy?

Anguloa clowesii 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. Anguloa clowesii can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (grown indoors / greenhouse in most US and UK homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature anguloa clowesii can survive?

What hardiness zone is anguloa clowesii?

Anguloa clowesii is rated USDA 10-11 (grown indoors / greenhouse in most US and UK homes) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can anguloa clowesii 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 anguloa clowesii 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.