Cold hardiness & minimum temperature

Is Burser's Saxifrage (Saxifraga burseriana)cold hardy? Hardiness zone & min temp

Also called Burser's Saxifrage, Kabschia Saxifrage.

More about burser's saxifrage

About Burser's Saxifrage

Saxifraga burseriana · also called Burser's Saxifrage, Kabschia Saxifrage · flowering

Burser's Saxifrage is a cushion-forming alpine perennial from the limestone screes of the eastern Alps. One of the earliest saxifrages to bloom, it produces large, solitary white or pale-yellow flowers on short red stems in late winter to early spring, emerging from tight mounds of grey-green, spine-tipped leaves. Ideal for alpine troughs.

Cold limit: USDA 4–8 · RHS H7 (-15–18°C)

Watch for — Crown rot: The most serious threat. Caused by moisture sitting in the tight cushion, especially with overhead watering or winter rain. Grow under an alpine house or lean-to glass in wet winters; use a grit topdressing around the collar.

What burser's saxifrage's hardiness rating actually means

Yes — burser's saxifrage is genuinely cold hardy. Rated RHS H7 and USDA 4–8, 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 4–8 — 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. Burser's Saxifrage is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for burser's saxifrage 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 burser's saxifrage go outside or overwinter — and where?

Plant it out within USDA 4–8 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 burser's saxifrage can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Burser's Saxifrage hardiness — frequently asked questions

Is burser's saxifrage cold hardy?

Yes — burser's saxifrage is genuinely cold hardy. Rated RHS H7 and USDA 4–8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Burser's Saxifrage is hardy across USDA 4–8; 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 burser's saxifrage can survive?

Minimum survivable temperature is roughly below about −20 °C. Burser's Saxifrage is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is burser's saxifrage?

Burser's Saxifrage is rated USDA 4–8 and RHS H7 — Hardy in the severest European continental winters.

Can burser's saxifrage survive winter outside?

Plant it out within USDA 4–8 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 burser's saxifrage 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.