Cold hardiness & minimum temperature

Is Panama Rose Shrub (Rondeletia leucophylla)cold hardy? Hardiness zone & min temp

Also called Panama Rose, Bush Pentas, Pink Rondeletia.

More about panama rose shrub

About Panama Rose Shrub

Rondeletia leucophylla · also called Panama Rose, Bush Pentas · tropical

Panama Rose is a compact, evergreen tropical shrub that bears dense clusters of small, sweetly fragrant pink flowers with a yellow eye almost continuously in warm climates. It thrives in full sun with well-drained, slightly acidic soil and is moderately drought-tolerant once established. Best suited to USDA zones 9–11.

Cold limit: USDA 9-11 · RHS H2 (10–35°C)

Watch for — Frost damage on young growth: Temperatures below 2°C (35°F) damage new growth; a hard freeze damages woody stems on young plants. Established mature plants tolerate brief dips to just below freezing. Protect with fleece in marginal climates and do not prune cold-damaged tissue until spring regrowth confirms what is dead.

What panama rose shrub's hardiness rating actually means

Panama Rose Shrub 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 — 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. Panama Rose Shrub shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for panama rose shrub 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 panama rose shrub go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 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 panama rose shrub 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 panama rose shrub

Panama Rose Shrub 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.

Panama Rose Shrub hardiness — frequently asked questions

Is panama rose shrub cold hardy?

Panama Rose Shrub 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 (and sheltered UK gardens) panama rose shrub can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature panama rose shrub can survive?

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

What hardiness zone is panama rose shrub?

Panama Rose Shrub is rated USDA 9-11 and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can panama rose shrub survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 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 panama rose shrub 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.