Cold hardiness & minimum temperature

Is Mophead Hydrangea 'Cityline Paris' (Hydrangea macrophylla 'Paris Rapa')cold hardy? Hardiness zone & min temp

Also called Cityline Paris Hydrangea.

More about mophead hydrangea 'cityline paris'

About Mophead Hydrangea 'Cityline Paris'

Hydrangea macrophylla 'Paris Rapa' · also called Cityline Paris Hydrangea · flowering

'Cityline Paris' is a compact dwarf mophead hydrangea bred for patios and small borders, carrying large rounded heads that open bright pink to red and age to attractive green. Naturally tidy at under a metre, disease-resistant and free-flowering, it wants moist, rich soil, dappled light and shelter from harsh afternoon sun.

Cold limit: USDA 5-9 · RHS H5 (-15 to 27°C)

Watch for — No flowers after pruning: Mopheads bloom mainly on old wood; cutting back hard in spring or winter dieback removes the flower buds. Prune only to deadhead and shape just after flowering.

What mophead hydrangea 'cityline paris''s hardiness rating actually means

Yes — mophead hydrangea 'cityline paris' is genuinely cold hardy. Rated RHS H5 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 5-9 — 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

Minimum survivable temperature is roughly about −15 to −10 °C. Mophead Hydrangea 'Cityline Paris' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for mophead hydrangea 'cityline paris' as it gets too cold:

It tolerates winter lows to about −15 to −10 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can mophead hydrangea 'cityline paris' go outside or overwinter — and where?

Plant it out within USDA 5-9 and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

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 mophead hydrangea 'cityline paris' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Mophead Hydrangea 'Cityline Paris' hardiness — frequently asked questions

Is mophead hydrangea 'cityline paris' cold hardy?

Yes — mophead hydrangea 'cityline paris' is genuinely cold hardy. Rated RHS H5 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Mophead Hydrangea 'Cityline Paris' is hardy across USDA 5-9; it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature mophead hydrangea 'cityline paris' can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Mophead Hydrangea 'Cityline Paris' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is mophead hydrangea 'cityline paris'?

Mophead Hydrangea 'Cityline Paris' is rated USDA 5-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can mophead hydrangea 'cityline paris' survive winter outside?

Plant it out within USDA 5-9 and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to mophead hydrangea 'cityline paris' below its minimum temperature?

It tolerates winter lows to about −15 to −10 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.