Cold hardiness & minimum temperature

Is Water Spinach 'Bangkok Large Leaf' (Ipomoea aquatica 'Bangkok Large Leaf')cold hardy? Hardiness zone & min temp

Also called Bangkok large leaf water spinach, kangkong, morning glory vegetable.

More about water spinach 'bangkok large leaf'

About Water Spinach 'Bangkok Large Leaf'

Ipomoea aquatica 'Bangkok Large Leaf' · also called Bangkok large leaf water spinach, kangkong · edible

'Bangkok Large Leaf' is a broad-leaved kangkong grown for its tender, fast-growing shoots and large leaves used in Southeast Asian stir-fries. A semi-aquatic, heat-loving morning glory relative, it thrives in warmth and constant moisture or shallow water, cropping in 4-6 weeks and regrowing repeatedly after cut-and-come-again harvesting through the summer.

Cold limit: USDA 10-12 (frost-tender; grown as a warm-season annual elsewhere) · RHS H1c (needs warmth; grown under cover or as a summer annual in the UK) (24-35°C)

Watch for — Cold sensitivity: Growth stalls below about 20°C and frost kills it. Grow only in warm weather, under cover, or indoors with bottom heat in cool climates.

What water spinach 'bangkok large leaf''s hardiness rating actually means

Water Spinach 'Bangkok Large Leaf' 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 10-12 (frost-tender; grown as a warm-season annual 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 5 °C (and never frost). Water Spinach 'Bangkok Large Leaf' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for water spinach 'bangkok large leaf' 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 water spinach 'bangkok large leaf' 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 water spinach 'bangkok large leaf' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Water Spinach 'Bangkok Large Leaf' hardiness — frequently asked questions

Is water spinach 'bangkok large leaf' cold hardy?

Water Spinach 'Bangkok Large Leaf' 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. Water Spinach 'Bangkok Large Leaf' can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (frost-tender; grown as a warm-season annual elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature water spinach 'bangkok large leaf' can survive?

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

What hardiness zone is water spinach 'bangkok large leaf'?

Water Spinach 'Bangkok Large Leaf' is rated USDA 10-12 (frost-tender; grown as a warm-season annual elsewhere) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can water spinach 'bangkok large leaf' 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 water spinach 'bangkok large leaf' 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.