Cold hardiness & minimum temperature

Is Pelargonium peltatum 'Roi des Balcons Lilas' (Pelargonium peltatum 'Roi des Balcons Lilas')cold hardy? Hardiness zone & min temp

Also called Balcony lilac geranium, Roi des Balcons ivy pelargonium.

More about pelargonium peltatum 'roi des balcons lilas'

About Pelargonium peltatum 'Roi des Balcons Lilas'

Pelargonium peltatum 'Roi des Balcons Lilas' · also called Balcony lilac geranium, Roi des Balcons ivy pelargonium · flowering

'Roi des Balcons Lilas' is a classic Continental balcony pelargonium — a vigorous ivy-leaved trailer smothered in single lilac-pink flowers all summer. Long stems cascade dramatically from window boxes and railing planters. Heat- and drought-tolerant once established, it needs full sun, free-draining compost, generous feeding and frost-free overwintering.

Cold limit: USDA 9-11 (frost-tender; grown as an annual or overwintered frost-free in colder zones) · RHS H2 (10-24°C)

What pelargonium peltatum 'roi des balcons lilas''s hardiness rating actually means

Hardiness works differently for pelargonium peltatum 'roi des balcons lilas': 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 H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 9-11 (frost-tender; grown as an annual or overwintered frost-free in colder 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 pelargonium peltatum 'roi des balcons lilas' 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 pelargonium peltatum 'roi des balcons lilas' 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 pelargonium peltatum 'roi des balcons lilas' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline pelargonium peltatum 'roi des balcons lilas'

Pelargonium peltatum 'Roi des Balcons Lilas' 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.

Pelargonium peltatum 'Roi des Balcons Lilas' hardiness — frequently asked questions

Is pelargonium peltatum 'roi des balcons lilas' cold hardy?

Hardiness works differently for pelargonium peltatum 'roi des balcons lilas': 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. Pelargonium peltatum 'Roi des Balcons Lilas' is grown 9-11 (frost-tender; grown as an annual or overwintered frost-free in colder zones); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature pelargonium peltatum 'roi des balcons lilas' 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 pelargonium peltatum 'roi des balcons lilas'?

Pelargonium peltatum 'Roi des Balcons Lilas' is rated USDA 9-11 (frost-tender; grown as an annual or overwintered frost-free in colder zones) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can pelargonium peltatum 'roi des balcons lilas' 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 pelargonium peltatum 'roi des balcons lilas' 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.