Cold hardiness & minimum temperature

Is Snapdragon 'Madame Butterfly' (Antirrhinum majus 'Madame Butterfly')cold hardy? Hardiness zone & min temp

Also called Azalea-flowered snapdragon.

More about snapdragon 'madame butterfly'

About Snapdragon 'Madame Butterfly'

Antirrhinum majus 'Madame Butterfly' · also called Azalea-flowered snapdragon · flowering

'Madame Butterfly' is a tall snapdragon with double, open azalea-type flowers that lack the snapping hinge, giving full, ruffled spikes in soft pastels and rich shades. A superb cut flower grown as an annual, it wants full sun, cool weather and free-draining soil. Pinch for branching and deadhead to keep the spikes coming.

Cold limit: USDA 7-11 as a short-lived perennial; grown as an annual elsewhere · RHS H3 (10-24°C)

What snapdragon 'madame butterfly''s hardiness rating actually means

Hardiness works differently for snapdragon 'madame butterfly': 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 7-11 as a short-lived perennial; grown as an 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 snapdragon 'madame butterfly' 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 snapdragon 'madame butterfly' 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 snapdragon 'madame butterfly' 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 snapdragon 'madame butterfly'

Snapdragon 'Madame Butterfly' 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.

Snapdragon 'Madame Butterfly' hardiness — frequently asked questions

Is snapdragon 'madame butterfly' cold hardy?

Hardiness works differently for snapdragon 'madame butterfly': 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. Snapdragon 'Madame Butterfly' is grown 7-11 as a short-lived perennial; grown as an annual elsewhere; you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature snapdragon 'madame butterfly' 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 snapdragon 'madame butterfly'?

Snapdragon 'Madame Butterfly' is rated USDA 7-11 as a short-lived perennial; grown as an annual elsewhere and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can snapdragon 'madame butterfly' 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 snapdragon 'madame butterfly' 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.