Cold hardiness & minimum temperature

Is Accent Scarlet Busy Lizzie (Impatiens walleriana)cold hardy? Hardiness zone & min temp

Also called Busy Lizzie, Balsam, Patient Lucy, Touch-Me-Not.

More about accent scarlet busy lizzie

About Accent Scarlet Busy Lizzie

Impatiens walleriana · also called Busy Lizzie, Balsam · flowering

Accent Scarlet Busy Lizzie is a compact, free-flowering series of Impatiens walleriana bearing vivid scarlet blooms all summer. Perfect for shady beds, containers, and hanging baskets, it is one of the most popular summer bedding plants. Note that Impatiens downy mildew has severely affected outdoor plantings in recent years. Mildly toxic to pets.

Cold limit: USDA 10-12 (grown as a half-hardy annual in zones 2-9) · RHS H1c (10 to 30°C)

What accent scarlet busy lizzie's hardiness rating actually means

Hardiness works differently for accent scarlet busy lizzie: 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 10-12 (grown as a half-hardy annual in zones 2-9) — 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 accent scarlet busy lizzie 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 accent scarlet busy lizzie 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 accent scarlet busy lizzie can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Frost protection for borderline accent scarlet busy lizzie

Accent Scarlet Busy Lizzie 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.

Accent Scarlet Busy Lizzie hardiness — frequently asked questions

Is accent scarlet busy lizzie cold hardy?

Hardiness works differently for accent scarlet busy lizzie: 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. Accent Scarlet Busy Lizzie is grown 10-12 (grown as a half-hardy annual in zones 2-9); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature accent scarlet busy lizzie 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 accent scarlet busy lizzie?

Accent Scarlet Busy Lizzie is rated USDA 10-12 (grown as a half-hardy annual in zones 2-9) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can accent scarlet busy lizzie 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 accent scarlet busy lizzie 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.