Cold hardiness & minimum temperature

Is Variegated Cord Grass (Spartina pectinata 'Aureomarginata')cold hardy? Hardiness zone & min temp

Also called variegated prairie cord grass, gold-edge cord grass.

More about variegated cord grass

About Variegated Cord Grass

Spartina pectinata 'Aureomarginata' · also called variegated prairie cord grass, gold-edge cord grass · flowering

Variegated cord grass is a vigorous, moisture-loving prairie grass with arching blades edged in golden yellow that age to warm bronze in autumn. Spreading by tough rhizomes, it excels in pond margins, rain gardens and wet clay where few grasses thrive. It reaches around 1.5 metres and is exceptionally cold-hardy, but can spread strongly in ideal conditions.

Cold limit: USDA 4-9 (very cold-hardy; dies to ground in winter) · RHS H6 (-34 to 35°C)

What variegated cord grass's hardiness rating actually means

Yes — variegated cord grass is genuinely cold hardy. Rated RHS H6 and USDA 4-9 (very cold-hardy; dies to ground in winter), 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 (very cold-hardy; dies to ground in winter) — 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. Variegated Cord Grass is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for variegated cord grass 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 variegated cord grass go outside or overwinter — and where?

Plant it out within USDA 4-9 (very cold-hardy; dies to ground in winter) 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 variegated cord grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Variegated Cord Grass hardiness — frequently asked questions

Is variegated cord grass cold hardy?

Yes — variegated cord grass is genuinely cold hardy. Rated RHS H6 and USDA 4-9 (very cold-hardy; dies to ground in winter), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Variegated Cord Grass is hardy across USDA 4-9 (very cold-hardy; dies to ground in winter); 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 variegated cord grass can survive?

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

What hardiness zone is variegated cord grass?

Variegated Cord Grass is rated USDA 4-9 (very cold-hardy; dies to ground in winter) and RHS H6 — Hardy throughout the UK and northern Europe.

Can variegated cord grass survive winter outside?

Plant it out within USDA 4-9 (very cold-hardy; dies to ground in winter) 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 variegated cord grass 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.