Cold hardiness & minimum temperature

Is Ravenna Grass (Saccharum ravennae)cold hardy? Hardiness zone & min temp

Also called ravenna grass, hardy pampas grass, plume grass.

More about ravenna grass

About Ravenna Grass

Saccharum ravennae · also called ravenna grass, hardy pampas grass · flowering

Ravenna grass is a towering, cold-hardy ornamental grass grown as a pampas grass substitute in northern gardens. From a clumping base it throws up silvery-grey feathery plumes on stems reaching 3-4 metres in late summer. It loves full sun and tolerates poor, dry soil once established, but can self-seed aggressively and is invasive in some regions.

Cold limit: USDA 6-9 (root-hardy, dies back to ground each winter in colder zones) · RHS H5 (-20 to 35°C)

Watch for — Crown rot in wet soil: Waterlogged winter ground rots the crown. Plant in free-draining soil and avoid low spots where water collects.

What ravenna grass's hardiness rating actually means

Yes — ravenna grass is genuinely cold hardy. Rated RHS H5 and USDA 6-9 (root-hardy, dies back to ground each winter in colder zones), 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 6-9 (root-hardy, dies back to ground each winter 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

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

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

Plant it out within USDA 6-9 (root-hardy, dies back to ground each winter in colder zones) 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 ravenna grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Ravenna Grass hardiness — frequently asked questions

Is ravenna grass cold hardy?

Yes — ravenna grass is genuinely cold hardy. Rated RHS H5 and USDA 6-9 (root-hardy, dies back to ground each winter in colder zones), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Ravenna Grass is hardy across USDA 6-9 (root-hardy, dies back to ground each winter in colder zones); 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 ravenna grass can survive?

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

What hardiness zone is ravenna grass?

Ravenna Grass is rated USDA 6-9 (root-hardy, dies back to ground each winter in colder zones) and RHS H5 — Hardy in most of the UK and in cold winters.

Can ravenna grass survive winter outside?

Plant it out within USDA 6-9 (root-hardy, dies back to ground each winter in colder zones) 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 ravenna grass 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.