Cold hardiness & minimum temperature

Is Common Tussock Grass (Poa labillardieri)cold hardy? Hardiness zone & min temp

Also called common tussock grass, tussock poa, tussock grass.

More about common tussock grass

About Common Tussock Grass

Poa labillardieri · also called common tussock grass, tussock poa · flowering

Common tussock grass is a large Australian native bunchgrass forming dramatic, arching mounds of fine, blue-grey to grey-green foliage. Tall, nodding flower panicles emerge in spring and early summer. Remarkably tough and adaptable, it tolerates drought, periodic flooding, poor soils, and coastal exposure. A key species in Australian ecological restoration and increasingly popular in naturalistic garden design.

Cold limit: USDA 7–11 · RHS H5 (−12°C to 42°C)

Watch for — Tussock decline / dead centre in old clumps: Very old tussocks (10+ years) may develop a hollow or dead centre as the plant matures. In garden settings, divide and replant vigorous outer sections in late winter or early spring. In natural revegetation, this is part of the normal life cycle.

What common tussock grass's hardiness rating actually means

Yes — common tussock grass is genuinely cold hardy. Rated RHS H5 and USDA 7–11, 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 7–11 — 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. Common Tussock Grass is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 7–11 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 common tussock grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Common Tussock Grass hardiness — frequently asked questions

Is common tussock grass cold hardy?

Yes — common tussock grass is genuinely cold hardy. Rated RHS H5 and USDA 7–11, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Common Tussock Grass is hardy across USDA 7–11; 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 common tussock grass can survive?

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

What hardiness zone is common tussock grass?

Common Tussock Grass is rated USDA 7–11 and RHS H5 — Hardy in most of the UK and in cold winters.

Can common tussock grass survive winter outside?

Plant it out within USDA 7–11 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 common tussock 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.