Cold hardiness & minimum temperature

Is Schlim's Phragmipedium (Phragmipedium schlimii)cold hardy? Hardiness zone & min temp

Also called Schlim's Slipper Orchid, Pink Phrag.

More about schlim's phragmipedium

About Schlim's Phragmipedium

Phragmipedium schlimii · also called Schlim's Slipper Orchid, Pink Phrag · tropical

Phragmipedium schlimii is a delicate Colombian slipper orchid producing elegant, rose-pink and white pouched flowers on multi-flowered spikes. It grows in cool, wet mountain habitats and requires consistently moist conditions, cool temperatures, and high humidity. Orchidaceae; pet-safe.

Cold limit: USDA 10-12 (indoor cool-growing specialist) · RHS H1c (10-22°C)

Watch for — Crown rot in warm conditions: Warm temperatures above 24°C combined with wet crowns can cause fatal rot. Keep cool and ensure water drains away from the leaf fan.

What schlim's phragmipedium's hardiness rating actually means

Schlim's Phragmipedium 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 (indoor cool-growing specialist) — 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). Schlim's Phragmipedium has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Schlim's Phragmipedium hardiness — frequently asked questions

Is schlim's phragmipedium cold hardy?

Schlim's Phragmipedium 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. Schlim's Phragmipedium can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor cool-growing specialist)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature schlim's phragmipedium can survive?

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

What hardiness zone is schlim's phragmipedium?

Schlim's Phragmipedium is rated USDA 10-12 (indoor cool-growing specialist) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can schlim's phragmipedium 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 schlim's phragmipedium 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.