Cold hardiness & minimum temperature

Is Haworthia Lockwoodii (Haworthia lockwoodii)cold hardy? Hardiness zone & min temp

Also called Lockwood's haworthia, Dry-leaf haworthia.

More about haworthia lockwoodii

About Haworthia Lockwoodii

Haworthia lockwoodii · also called Lockwood's haworthia, Dry-leaf haworthia · houseplant

Haworthia lockwoodii is a distinctive rosette succulent whose incurved leaves dry to papery, translucent tips that shield the plant from harsh sun in habitat. It stays small, retracts into the soil during drought, and needs gritty soil with restrained watering. Slow and undemanding, and non-toxic to cats and dogs per the ASPCA.

Cold limit: USDA 10-11 (indoor in most US homes) · RHS H1c (15-27°C)

What haworthia lockwoodii's hardiness rating actually means

Haworthia Lockwoodii 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 10-11 (indoor in most US homes) — 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). Haworthia Lockwoodii has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Haworthia Lockwoodii hardiness — frequently asked questions

Is haworthia lockwoodii cold hardy?

Haworthia Lockwoodii 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. Haworthia Lockwoodii can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature haworthia lockwoodii can survive?

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

What hardiness zone is haworthia lockwoodii?

Haworthia Lockwoodii is rated USDA 10-11 (indoor in most US homes) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can haworthia lockwoodii 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 haworthia lockwoodii 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.