Cold hardiness & minimum temperature

Is Begonia × tuberhybrida 'Nonstop Rose' (Begonia × tuberhybrida 'Nonstop Rose')cold hardy? Hardiness zone & min temp

Also called Nonstop Rose Begonia, Tuberous Begonia Rose.

More about begonia × tuberhybrida 'nonstop rose'

About Begonia × tuberhybrida 'Nonstop Rose'

Begonia × tuberhybrida 'Nonstop Rose' · also called Nonstop Rose Begonia, Tuberous Begonia Rose · flowering

Nonstop Rose is a compact tuberous begonia bearing fully double, rose-form blooms in deep rose-pink that flower continuously from early summer to frost. Bred for shade and containers, it prefers cool, bright, sheltered spots and dislikes heat and direct sun. Tubers can be lifted, dried, and stored frost-free over winter to regrow the following year.

Cold limit: USDA 9-11 (lift and store tubers in colder zones) · RHS H2 (13-24°C)

What begonia × tuberhybrida 'nonstop rose''s hardiness rating actually means

Begonia × tuberhybrida 'Nonstop Rose' 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 (lift and store tubers in colder zones) — 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. Begonia × tuberhybrida 'Nonstop Rose' shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for begonia × tuberhybrida 'nonstop rose' 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 begonia × tuberhybrida 'nonstop rose' go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (lift and store tubers in colder zones) 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 begonia × tuberhybrida 'nonstop rose' 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 begonia × tuberhybrida 'nonstop rose'

Begonia × tuberhybrida 'Nonstop Rose' 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.

Begonia × tuberhybrida 'Nonstop Rose' hardiness — frequently asked questions

Is begonia × tuberhybrida 'nonstop rose' cold hardy?

Begonia × tuberhybrida 'Nonstop Rose' 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 (lift and store tubers in colder zones) (and sheltered UK gardens) begonia × tuberhybrida 'nonstop rose' can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature begonia × tuberhybrida 'nonstop rose' can survive?

What hardiness zone is begonia × tuberhybrida 'nonstop rose'?

Begonia × tuberhybrida 'Nonstop Rose' is rated USDA 9-11 (lift and store tubers in colder zones) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can begonia × tuberhybrida 'nonstop rose' survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (lift and store tubers in colder zones) 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 begonia × tuberhybrida 'nonstop rose' 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.