Cold hardiness & minimum temperature

Is Physocarpus opulifolius 'Summer Wine' (Physocarpus opulifolius 'Seward' (Summer Wine))cold hardy? Hardiness zone & min temp

Also called Summer Wine ninebark, compact purple ninebark.

More about physocarpus opulifolius 'summer wine'

About Physocarpus opulifolius 'Summer Wine'

Physocarpus opulifolius 'Seward' (Summer Wine) · also called Summer Wine ninebark, compact purple ninebark · flowering

'Summer Wine' is a more compact, finely textured purple ninebark, with deep wine-red leaves on dense, arching branches and pinkish-white flower clusters in early summer. Bred from a 'Diabolo' cross, it keeps richer colour on a tidier, fuller frame ideal for smaller gardens. Extremely hardy and adaptable, it performs best in full sun on most soils.

Cold limit: USDA 3-7 · RHS H7 (-37 to 32°C)

What physocarpus opulifolius 'summer wine''s hardiness rating actually means

Yes — physocarpus opulifolius 'summer wine' is genuinely cold hardy. Rated RHS H7 and USDA 3-7, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 3-7 — 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 below about −20 °C. Physocarpus opulifolius 'Summer Wine' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for physocarpus opulifolius 'summer wine' as it gets too cold:

It tolerates winter lows to about −20 °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 physocarpus opulifolius 'summer wine' go outside or overwinter — and where?

Plant it out within USDA 3-7 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 physocarpus opulifolius 'summer wine' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Physocarpus opulifolius 'Summer Wine' hardiness — frequently asked questions

Is physocarpus opulifolius 'summer wine' cold hardy?

Yes — physocarpus opulifolius 'summer wine' is genuinely cold hardy. Rated RHS H7 and USDA 3-7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Physocarpus opulifolius 'Summer Wine' is hardy across USDA 3-7; 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 physocarpus opulifolius 'summer wine' can survive?

Minimum survivable temperature is roughly below about −20 °C. Physocarpus opulifolius 'Summer Wine' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is physocarpus opulifolius 'summer wine'?

Physocarpus opulifolius 'Summer Wine' is rated USDA 3-7 and RHS H7 — Hardy in the severest European continental winters.

Can physocarpus opulifolius 'summer wine' survive winter outside?

Plant it out within USDA 3-7 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 physocarpus opulifolius 'summer wine' below its minimum temperature?

It tolerates winter lows to about −20 °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.