Cold hardiness & minimum temperature

Is Clematis 'Multi Blue' (Clematis 'Multi Blue')cold hardy? Hardiness zone & min temp

Also called Multi Blue clematis, double blue clematis.

More about clematis 'multi blue'

About Clematis 'Multi Blue'

Clematis 'Multi Blue' · also called Multi Blue clematis, double blue clematis · flowering

Clematis 'Multi Blue' is a distinctive double-flowered deciduous climber producing deep violet-blue blooms with a spiky pompon centre of narrow inner tepals. A sport of 'The President', it flowers on old wood in early summer and again on new growth later, suiting trellises, fences and large patio pots.

Cold limit: USDA 4-9 (outdoor garden climber) · RHS H6 (-20 to 27°C)

Watch for — Reversion to single flowers: Later-season and stressed flowers may open single rather than double; this is normal for 'Multi Blue' — the spiky double form appears mainly on overwintered old wood.

What clematis 'multi blue''s hardiness rating actually means

Yes — clematis 'multi blue' is genuinely cold hardy. Rated RHS H6 and USDA 4-9 (outdoor garden climber), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 4-9 (outdoor garden climber) — 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 −20 to −15 °C. Clematis 'Multi Blue' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for clematis 'multi blue' as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 clematis 'multi blue' go outside or overwinter — and where?

Plant it out within USDA 4-9 (outdoor garden climber) 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 clematis 'multi blue' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Clematis 'Multi Blue' hardiness — frequently asked questions

Is clematis 'multi blue' cold hardy?

Yes — clematis 'multi blue' is genuinely cold hardy. Rated RHS H6 and USDA 4-9 (outdoor garden climber), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Clematis 'Multi Blue' is hardy across USDA 4-9 (outdoor garden climber); 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 clematis 'multi blue' can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Clematis 'Multi Blue' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is clematis 'multi blue'?

Clematis 'Multi Blue' is rated USDA 4-9 (outdoor garden climber) and RHS H6 — Hardy throughout the UK and northern Europe.

Can clematis 'multi blue' survive winter outside?

Plant it out within USDA 4-9 (outdoor garden climber) 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 clematis 'multi blue' below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.