Cold hardiness & minimum temperature

Is Beni-kaze Hakone Grass (Hakonechloa macra 'Beni-kaze')cold hardy? Hardiness zone & min temp

Also called red wind hakone grass, beni-kaze japanese forest grass.

More about beni-kaze hakone grass

About Beni-kaze Hakone Grass

Hakonechloa macra 'Beni-kaze' · also called red wind hakone grass, beni-kaze japanese forest grass · flowering

Hakonechloa macra 'Beni-kaze', meaning 'red wind', is a green-leaved Japanese forest grass that turns striking shades of red, pink, and burgundy as autumn cools. Its arching blades cascade in soft mounds, thriving in part shade with rich, moist soil. A graceful deciduous grass valued for fiery seasonal colour in shaded borders and woodland plantings.

Cold limit: USDA 5-9 · RHS H6 (-1 to 24°C)

Watch for — Seasonal dieback: Foliage collapses and dies each autumn, which is normal; cut spent growth to the ground in late winter ahead of new spring shoots.

What beni-kaze hakone grass's hardiness rating actually means

Yes — beni-kaze hakone grass is genuinely cold hardy. Rated RHS H6 and USDA 5-9, 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 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 −20 to −15 °C. Beni-kaze Hakone Grass is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for beni-kaze hakone 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 beni-kaze hakone grass 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 beni-kaze hakone grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Beni-kaze Hakone Grass hardiness — frequently asked questions

Is beni-kaze hakone grass cold hardy?

Yes — beni-kaze hakone grass is genuinely cold hardy. Rated RHS H6 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Beni-kaze Hakone Grass 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 beni-kaze hakone grass can survive?

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

What hardiness zone is beni-kaze hakone grass?

Beni-kaze Hakone Grass is rated USDA 5-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can beni-kaze hakone grass 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 beni-kaze hakone 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.