Cold hardiness & minimum temperature

Is Begonia 'Pin Up Flame' (Begonia × tuberhybrida 'Pin Up Flame')cold hardy? Hardiness zone & min temp

Also called pin up flame begonia, bicolor tuberous begonia.

More about begonia 'pin up flame'

About Begonia 'Pin Up Flame'

Begonia × tuberhybrida 'Pin Up Flame' · also called pin up flame begonia, bicolor tuberous begonia · flowering

Begonia 'Pin Up Flame' is a tuberous begonia with large single flowers in creamy yellow boldly edged in fiery orange-red, an eye-catching bicolour that holds an RHS Award of Garden Merit. Grown as a half-hardy annual or lifted tuber, it flowers all summer in partial shade in moist, free-draining soil and is stored dry over winter.

Cold limit: USDA 9-11 outdoors; grown as an annual or lifted tuber in cooler zones · RHS H2 (RHS-rated, frost-tender; lift and store tubers over winter) (13-24°C (frost-tender))

Watch for — Tuber rot: Wet compost in growth or damp storage rots the tuber. Use free-draining compost and overwinter dry tubers somewhere cool and frost-free.

What begonia 'pin up flame''s hardiness rating actually means

Hardiness works differently for begonia 'pin up flame': it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". 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 outdoors; grown as an annual or lifted tuber in cooler 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

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for begonia 'pin up flame' as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can begonia 'pin up flame' go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

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 'pin up flame' 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 'pin up flame'

Begonia 'Pin Up Flame' is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Begonia 'Pin Up Flame' hardiness — frequently asked questions

Is begonia 'pin up flame' cold hardy?

Hardiness works differently for begonia 'pin up flame': it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Begonia 'Pin Up Flame' is grown 9-11 outdoors; grown as an annual or lifted tuber in cooler zones; you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature begonia 'pin up flame' can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is begonia 'pin up flame'?

Begonia 'Pin Up Flame' is rated USDA 9-11 outdoors; grown as an annual or lifted tuber in cooler zones and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can begonia 'pin up flame' survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect begonia 'pin up flame' from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.