Cold hardiness & minimum temperature

Is Moudry Black Fountain Grass (Pennisetum alopecuroides 'Moudry')cold hardy? Hardiness zone & min temp

Also called moudry fountain grass, black-flowered fountain grass.

More about moudry black fountain grass

About Moudry Black Fountain Grass

Pennisetum alopecuroides 'Moudry' · also called moudry fountain grass, black-flowered fountain grass · flowering

'Moudry' is the black-plumed fountain grass, with broad, glossy dark-green blades and dramatic deep purple-black foxtail flowers in late summer and autumn. It forms a substantial mounded clump in full sun. Striking but vigorous, it self-seeds freely and is best where its prolific seedlings can be managed in US and UK gardens.

Cold limit: USDA 5-9 · RHS H5 (-1 to 30°C)

Watch for — Crown rot in wet winters: Soggy, poorly drained ground rots the crown. Improve drainage and keep mulch off the base over winter.

What moudry black fountain grass's hardiness rating actually means

Yes — moudry black fountain grass is genuinely cold hardy. Rated RHS H5 and USDA 5-9, 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 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 −15 to −10 °C. Moudry Black Fountain Grass is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for moudry black fountain 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 moudry black fountain 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 moudry black fountain grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Moudry Black Fountain Grass hardiness — frequently asked questions

Is moudry black fountain grass cold hardy?

Yes — moudry black fountain grass is genuinely cold hardy. Rated RHS H5 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Moudry Black Fountain 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 moudry black fountain grass can survive?

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

What hardiness zone is moudry black fountain grass?

Moudry Black Fountain Grass is rated USDA 5-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can moudry black fountain 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 moudry black fountain 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.