Cold hardiness & minimum temperature

Is Greater Quaking Grass (Briza maxima)cold hardy? Hardiness zone & min temp

Also called greater quaking grass, big quaking grass, rattlesnake grass.

More about greater quaking grass

About Greater Quaking Grass

Briza maxima · also called greater quaking grass, big quaking grass · flowering

Greater quaking grass (Briza maxima) is a self-seeding cool-season annual prized for nodding, locket-shaped spikelets that shimmer and rattle in the breeze. Grown in full sun on lean, well-drained soil, it forms a loose tuft of fine green blades topped by airy panicles that ripen from green to straw, excellent fresh or dried for arrangements.

Cold limit: USDA Grown as a cool-season annual; self-sows in zones 5-10 · RHS H3 (10-25°C)

What greater quaking grass's hardiness rating actually means

Hardiness works differently for greater quaking grass: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". Its RHS rating of H3 means: Half-hardy — comes through mild UK winters outside but is killed by a hard freeze. On the US scale that maps to USDA Grown as a cool-season annual; self-sows in zones 5-10 — 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

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for greater quaking grass as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can greater quaking grass go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

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 greater quaking grass can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H3 figure above.

Frost protection for borderline greater quaking grass

Greater Quaking Grass is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Greater Quaking Grass hardiness — frequently asked questions

Is greater quaking grass cold hardy?

Hardiness works differently for greater quaking grass: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Greater Quaking Grass is grown Grown as a cool-season annual; self-sows in zones 5-10; you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature greater quaking grass can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is greater quaking grass?

Greater Quaking Grass is rated USDA Grown as a cool-season annual; self-sows in zones 5-10 and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can greater quaking grass survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect greater quaking grass from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.