Cold hardiness & minimum temperature

Is Boston Fern 'Dallas' (Nephrolepis exaltata 'Dallas')cold hardy? Hardiness zone & min temp

Also called Dallas Jewel fern, Compact Boston fern.

More about boston fern 'dallas'

About Boston Fern 'Dallas'

Nephrolepis exaltata 'Dallas' · also called Dallas Jewel fern, Compact Boston fern · houseplant

'Dallas' is a compact, easy-care Boston fern with dense, arching fronds that stays smaller and more upright than the classic species, making it ideal for tight shelves and bathrooms. It thrives in bright indirect light, consistently moist soil and humid air, and is fully pet-safe. Less leaf-drop than standard Boston ferns.

Cold limit: USDA 9-11 outdoors; grown as a houseplant in most US homes · RHS H1c (16-24°C)

Watch for — Yellowing, dropping fronds: Usually overwatering and soggy roots, or cold draughts. Check drainage, let the surface dry slightly between waterings, and move away from vents.

What boston fern 'dallas''s hardiness rating actually means

Boston Fern 'Dallas' 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 9-11 outdoors; grown as a houseplant in most US homes — 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). Boston Fern 'Dallas' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for boston fern 'dallas' 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 boston fern 'dallas' 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 boston fern 'dallas' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Boston Fern 'Dallas' hardiness — frequently asked questions

Is boston fern 'dallas' cold hardy?

Boston Fern 'Dallas' 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. Boston Fern 'Dallas' can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 outdoors; grown as a houseplant in most US homes); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature boston fern 'dallas' can survive?

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

What hardiness zone is boston fern 'dallas'?

Boston Fern 'Dallas' is rated USDA 9-11 outdoors; grown as a houseplant in most US homes and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can boston fern 'dallas' 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 boston fern 'dallas' 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.