Cold hardiness & minimum temperature

Is Autumn Moor Grass (Sesleria autumnalis)cold hardy? Hardiness zone & min temp

Also called autumn moor grass, fall moor grass.

More about autumn moor grass

About Autumn Moor Grass

Sesleria autumnalis · also called autumn moor grass, fall moor grass · flowering

Autumn moor grass (Sesleria autumnalis) is a tough, semi-evergreen clumping grass forming neat mounds of chartreuse-green blades. Native to southeastern European limestone hills, it tolerates drought, poor soil and partial shade once established. Slender silvery flower spikes appear in late summer above the foliage, making it a reliable, low-care choice for edging, mass plantings and naturalistic borders.

Cold limit: USDA 5-9 · RHS H7 (-29 to 30°C)

Watch for — Crown rot in wet soil: Heavy, poorly drained or waterlogged ground rots the crown over winter. Plant on free-draining or raised, gritty soil and never let it sit wet.

What autumn moor grass's hardiness rating actually means

Yes — autumn moor grass is genuinely cold hardy. Rated RHS H7 and USDA 5-9, 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 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 below about −20 °C. Autumn Moor Grass is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for autumn moor grass 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 autumn moor 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 autumn moor grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Autumn Moor Grass hardiness — frequently asked questions

Is autumn moor grass cold hardy?

Yes — autumn moor grass is genuinely cold hardy. Rated RHS H7 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Autumn Moor 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 autumn moor grass can survive?

Minimum survivable temperature is roughly below about −20 °C. Autumn Moor Grass is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is autumn moor grass?

Autumn Moor Grass is rated USDA 5-9 and RHS H7 — Hardy in the severest European continental winters.

Can autumn moor 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 autumn moor grass 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.