Cold hardiness & minimum temperature

Is Elk Horns Pig's Ear (Cotyledon orbiculata 'Elk Horns')cold hardy? Hardiness zone & min temp

Also called Elk Horns Pig's Ear, Elk Horns Cotyledon.

More about elk horns pig's ear

About Elk Horns Pig's Ear

Cotyledon orbiculata 'Elk Horns' · also called Elk Horns Pig's Ear, Elk Horns Cotyledon · houseplant

A sculptural South African succulent cultivar whose powdery silver-white leaves develop distinctively pronged, antler-like tips as they mature — giving rise to the 'Elk Horns' name. Slow-growing and drought-adapted, it needs bright sun, extremely free-draining soil, and infrequent deep watering to thrive. Keep away from all pets — all Cotyledon contain cardiac glycosides.

Cold limit: USDA 9b–11b · RHS H2 (-4 to 35°C)

Watch for — Root and stem rot from overwatering: The number-one cause of death. Ensure soil dries fully between waterings and use perfectly draining soil. Reduce watering dramatically in winter or cool cloudy weather.

What elk horns pig's ear's hardiness rating actually means

Elk Horns Pig's Ear 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 9b–11b — 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. Elk Horns Pig's Ear shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for elk horns pig's ear 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 elk horns pig's ear go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9b–11b 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 elk horns pig's ear 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 elk horns pig's ear

Elk Horns Pig's Ear 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.

Elk Horns Pig's Ear hardiness — frequently asked questions

Is elk horns pig's ear cold hardy?

Elk Horns Pig's Ear 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 9b–11b (and sheltered UK gardens) elk horns pig's ear can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature elk horns pig's ear can survive?

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

What hardiness zone is elk horns pig's ear?

Elk Horns Pig's Ear is rated USDA 9b–11b and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can elk horns pig's ear survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9b–11b 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 elk horns pig's ear 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.