Cold hardiness & minimum temperature

Is Reticulate Pseuderanthemum (Pseuderanthemum reticulatum)cold hardy? Hardiness zone & min temp

Also called Reticulate Pseuderanthemum, Golden Pseuderanthemum, Yellow-Vein Eranthemum, Golden Net Bush.

More about reticulate pseuderanthemum

About Reticulate Pseuderanthemum

Pseuderanthemum reticulatum · also called Reticulate Pseuderanthemum, Golden Pseuderanthemum · tropical

A striking evergreen shrub from Polynesia prized for its glossy green leaves threaded with vivid golden-yellow veins. It thrives in warm, humid environments with bright indirect light and consistently moist soil. Indoors it makes an eye-catching foliage specimen; outdoors it suits tropical and subtropical gardens year-round.

Cold limit: USDA 10-11 · RHS H1b (18–27°C (min. 15°C))

Watch for — Brown leaf tips and edges: Usually caused by low humidity, dry draughts, or underwatering. Increase ambient humidity with a pebble tray or humidifier, keep away from heating vents, and ensure the soil does not dry out completely.

What reticulate pseuderanthemum's hardiness rating actually means

Reticulate Pseuderanthemum 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 H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA 10-11 — 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 10 °C (sustained cold below this is damaging). Reticulate Pseuderanthemum has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for reticulate pseuderanthemum as it gets too cold:

Below about about 10 °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 reticulate pseuderanthemum go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °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 reticulate pseuderanthemum can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Reticulate Pseuderanthemum hardiness — frequently asked questions

Is reticulate pseuderanthemum cold hardy?

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

What is the minimum temperature reticulate pseuderanthemum can survive?

What hardiness zone is reticulate pseuderanthemum?

Reticulate Pseuderanthemum is rated USDA 10-11 and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can reticulate pseuderanthemum survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °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 reticulate pseuderanthemum below its minimum temperature?

Below about about 10 °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.