Cold hardiness & minimum temperature

Is Plectranthus scutellarioides 'Wizard Scarlet' (Plectranthus scutellarioides 'Wizard Scarlet')cold hardy? Hardiness zone & min temp

Also called Wizard Scarlet Coleus, Scarlet Coleus.

More about plectranthus scutellarioides 'wizard scarlet'

About Plectranthus scutellarioides 'Wizard Scarlet'

Plectranthus scutellarioides 'Wizard Scarlet' · also called Wizard Scarlet Coleus, Scarlet Coleus · flowering

Wizard Scarlet is a compact, seed-grown coleus with rich scarlet-red leaves narrowly edged in green, prized for uniform habit and quick establishment. Part of the dwarf Wizard series, it suits bedding, edging, and containers in shade to part sun. Grown for vivid foliage, not its small flowers. Easy and fast, it is a tender perennial grown as an annual.

Cold limit: USDA 10-11 (grown as an annual in most zones) · RHS H1c (18-29°C)

What plectranthus scutellarioides 'wizard scarlet''s hardiness rating actually means

Hardiness works differently for plectranthus scutellarioides 'wizard scarlet': 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 10-11 (grown as an annual in most zones) — 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 plectranthus scutellarioides 'wizard scarlet' 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 plectranthus scutellarioides 'wizard scarlet' 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 plectranthus scutellarioides 'wizard scarlet' 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 plectranthus scutellarioides 'wizard scarlet'

Plectranthus scutellarioides 'Wizard Scarlet' 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.

Plectranthus scutellarioides 'Wizard Scarlet' hardiness — frequently asked questions

Is plectranthus scutellarioides 'wizard scarlet' cold hardy?

Hardiness works differently for plectranthus scutellarioides 'wizard scarlet': 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. Plectranthus scutellarioides 'Wizard Scarlet' is grown 10-11 (grown as an annual in most zones); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature plectranthus scutellarioides 'wizard scarlet' 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 plectranthus scutellarioides 'wizard scarlet'?

Plectranthus scutellarioides 'Wizard Scarlet' is rated USDA 10-11 (grown as an annual in most zones) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can plectranthus scutellarioides 'wizard scarlet' 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 plectranthus scutellarioides 'wizard scarlet' 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.