Cold hardiness & minimum temperature

Is Sedum clavatum (Sedum clavatum)cold hardy? Hardiness zone & min temp

Also called Tiscalatengo gorge sedum.

More about sedum clavatum

About Sedum clavatum

Sedum clavatum · also called Tiscalatengo gorge sedum · houseplant

Sedum clavatum is a Mexican stonecrop forming neat rosettes of plump, club-shaped blue-green leaves coated in a pale waxy bloom, blushing pink at the tips in strong sun. It trails and clumps on short stems, bearing white star flowers in spring. Wanting full sun, gritty soil and dry roots, this easy, pet-safe sedum suits sunny sills and rockeries.

Cold limit: USDA 9-11 (frost-tender; protect below about 4°C) · RHS H2 (10-27°C)

What sedum clavatum's hardiness rating actually means

Sedum clavatum 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 9-11 (frost-tender; protect below about 4°C) — 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. Sedum clavatum shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for sedum clavatum 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 sedum clavatum go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (frost-tender; protect below about 4°C) 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 sedum clavatum 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 sedum clavatum

Sedum clavatum 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.

Sedum clavatum hardiness — frequently asked questions

Is sedum clavatum cold hardy?

Sedum clavatum 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 9-11 (frost-tender; protect below about 4°C) (and sheltered UK gardens) sedum clavatum can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature sedum clavatum can survive?

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

What hardiness zone is sedum clavatum?

Sedum clavatum is rated USDA 9-11 (frost-tender; protect below about 4°C) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can sedum clavatum survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (frost-tender; protect below about 4°C) 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 sedum clavatum 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.