Cold hardiness & minimum temperature

Is Reed-stem orchid (Epidendrum spp.)cold hardy? Hardiness zone & min temp

Also called Reed-stem orchid, Crucifix orchid, Fiery reed orchid, Reed orchid, Star orchid.

More about reed-stem orchid

About Reed-stem orchid

Epidendrum spp. · also called Reed-stem orchid, Crucifix orchid · flowering

The reed-stem orchid (Epidendrum spp.) is a vigorous, easy-to-grow orchid prized for dense clusters of bright, long-lasting flowers atop tall cane-like stems. Give it bright light, an open bark mix, warm days, and cool nights for repeat blooms. ASPCA lists it as non-toxic to cats, dogs, and horses, making it a pet-safe choice.

Cold limit: USDA USDA 9-11 outdoors; grown as a frost-free patio or indoor plant elsewhere (Nights 12-15C, days 15-32C)

Watch for — No repeat blooming: Reed-stems flower best with a daily temperature drop of 10-15F (about 6-8C) between day and night and bright light. Constant warm temperatures and low light suppress flowering.

What reed-stem orchid's hardiness rating actually means

Reed-stem orchid is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA USDA 9-11 outdoors; grown as a frost-free patio or indoor plant 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 1 to 5 °C — tolerates cold but no real frost. Reed-stem orchid shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for reed-stem orchid as it gets too cold:

Down to roughly about 1 to 5 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can reed-stem orchid go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA USDA 9-11 outdoors; grown as a frost-free patio or indoor plant elsewhere or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

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 reed-stem orchid can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline reed-stem orchid

Reed-stem orchid is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Reed-stem orchid hardiness — frequently asked questions

Is reed-stem orchid cold hardy?

Reed-stem orchid is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA USDA 9-11 outdoors; grown as a frost-free patio or indoor plant elsewhere (and sheltered UK gardens) reed-stem orchid can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature reed-stem orchid can survive?

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Reed-stem orchid shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is reed-stem orchid?

Reed-stem orchid is rated USDA USDA 9-11 outdoors; grown as a frost-free patio or indoor plant elsewhere and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can reed-stem orchid survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA USDA 9-11 outdoors; grown as a frost-free patio or indoor plant elsewhere or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect reed-stem orchid from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.