Cold hardiness & minimum temperature

Is Edith's Air Plant (Tillandsia edithiae)cold hardy? Hardiness zone & min temp

Also called Edith's Air Plant, Edith's Tillandsia.

More about edith's air plant

About Edith's Air Plant

Tillandsia edithiae · also called Edith's Air Plant, Edith's Tillandsia · tropical

Tillandsia edithiae is a xeric lithophytic air plant native to the Andean peaks near Sorata, Bolivia, where it grows at approximately 2,700 m altitude on sheer rock cliffs, often in large cascading colonies. Its compact grey-green rosettes produce attractive red bracts with violet-blue flowers and it is notably cold- and heat-tolerant for an air plant. It prefers bright light, low humidity, and fast-drying conditions, making it among the easier species to maintain as a mounted display. According to the ASPCA, Tillandsia (air plants) are non-toxic to cats and dogs.

Cold limit: USDA 9-12 (outdoor in frost-free to near-frost climates) · RHS H2 (5–32 °C)

Watch for — Slow drying leading to base rot: Even though this species is cold-tolerant, it is very susceptible to rot if water collects at the base or between leaves and does not dry quickly. Ensure the mount allows complete air exposure around the base and only mist — do not soak — unless drying conditions are very fast.

What edith's air plant's hardiness rating actually means

Edith's Air Plant 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 9-12 (outdoor in frost-free to near-frost climates) — 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. Edith's Air Plant shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for edith's air plant 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 edith's air plant go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-12 (outdoor in frost-free to near-frost climates) 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 edith's air plant 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 edith's air plant

Edith's Air Plant 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.

Edith's Air Plant hardiness — frequently asked questions

Is edith's air plant cold hardy?

Edith's Air Plant 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 9-12 (outdoor in frost-free to near-frost climates) (and sheltered UK gardens) edith's air plant can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature edith's air plant can survive?

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Edith's Air Plant shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is edith's air plant?

Edith's Air Plant is rated USDA 9-12 (outdoor in frost-free to near-frost climates) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can edith's air plant survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-12 (outdoor in frost-free to near-frost climates) 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 edith's air plant 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.