Cold hardiness & minimum temperature

Is Madonna White Snapdragon (Antirrhinum majus)cold hardy? Hardiness zone & min temp

Also called White Snapdragon, Madonna Snapdragon, Dragon Flower.

More about madonna white snapdragon

About Madonna White Snapdragon

Antirrhinum majus · also called White Snapdragon, Madonna Snapdragon · flowering

A pure white, tall-growing snapdragon cultivar producing elegant upright spikes to 90–100 cm, ideal for wedding floristry and formal cut-flower arrangements. Cool-season performer with excellent vase life. Grows best in full sun with fertile, well-drained soil. Non-toxic to pets per ASPCA listings for the species.

Cold limit: USDA 7–10 (perennial in mild climates; cool-season annual elsewhere) · RHS H3 (hardy to around -5°C with protection) (10–21°C)

What madonna white snapdragon's hardiness rating actually means

Hardiness works differently for madonna white snapdragon: 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 7–10 (perennial in mild climates; cool-season annual elsewhere) — 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 madonna white snapdragon 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 madonna white snapdragon 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 madonna white snapdragon 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 madonna white snapdragon

Madonna White Snapdragon 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.

Madonna White Snapdragon hardiness — frequently asked questions

Is madonna white snapdragon cold hardy?

Hardiness works differently for madonna white snapdragon: 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. Madonna White Snapdragon is grown 7–10 (perennial in mild climates; cool-season annual elsewhere); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature madonna white snapdragon 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 madonna white snapdragon?

Madonna White Snapdragon is rated USDA 7–10 (perennial in mild climates; cool-season annual elsewhere) and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can madonna white snapdragon 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 madonna white snapdragon 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.