Cold hardiness & minimum temperature

Is Nicotiana sylvestris (Nicotiana sylvestris)cold hardy? Hardiness zone & min temp

Also called Woodland Tobacco, South American Tobacco, Looking Glass Plant.

More about nicotiana sylvestris

About Nicotiana sylvestris

Nicotiana sylvestris · also called Woodland Tobacco, South American Tobacco · flowering

A stately, architectural flowering tobacco growing into a tall rosette of huge paddle-shaped leaves topped by drooping clusters of long, pure-white tubular flowers that perfume the evening air. Native to Argentina and Bolivia, woodland tobacco is grown as a dramatic back-of-border annual or short-lived perennial, drawing moths and hawk-moths to its night-scented blooms.

Cold limit: USDA 10-11 (grown as an annual or short-lived perennial; often self-seeds) · RHS H3 (15-27°C)

What nicotiana sylvestris's hardiness rating actually means

Hardiness works differently for nicotiana sylvestris: 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 H3 means: Half-hardy — comes through mild UK winters outside but is killed by a hard freeze. On the US scale that maps to USDA 10-11 (grown as an annual or short-lived perennial; often self-seeds) — 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 nicotiana sylvestris 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 nicotiana sylvestris 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 nicotiana sylvestris can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H3 figure above.

Frost protection for borderline nicotiana sylvestris

Nicotiana sylvestris 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.

Nicotiana sylvestris hardiness — frequently asked questions

Is nicotiana sylvestris cold hardy?

Hardiness works differently for nicotiana sylvestris: 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. Nicotiana sylvestris is grown 10-11 (grown as an annual or short-lived perennial; often self-seeds); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature nicotiana sylvestris 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 nicotiana sylvestris?

Nicotiana sylvestris is rated USDA 10-11 (grown as an annual or short-lived perennial; often self-seeds) and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can nicotiana sylvestris 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 nicotiana sylvestris 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.