Cold hardiness & minimum temperature

Is Creeping Gaultheria (Gaultheria nummularioides)cold hardy? Hardiness zone & min temp

Also called Creeping Gaultheria, Coin-leaved Gaultheria.

More about creeping gaultheria

About Creeping Gaultheria

Gaultheria nummularioides · also called Creeping Gaultheria, Coin-leaved Gaultheria · flowering

Gaultheria nummularioides is a prostrate, carpet-forming evergreen shrub native to the Himalayas, southern China (Yunnan, Tibet), and into Southeast Asia at elevations of 1,700–3,000 m, where it roots as it spreads across rocky, shaded slopes. It demands cool conditions, consistent moisture, and lime-free, humus-rich soil; it is only marginally frost-hardy and in the UK requires a sheltered, south- or west-facing microclimate with good drainage to avoid winter losses. Small white bell-shaped flowers in summer are followed by blue-black berries. Like all Gaultheria, it contains methyl salicylate and is toxic to cats and dogs.

Cold limit: USDA 7-9 · RHS H4 (-5 to 20°C)

Watch for — Winter kill in cold or exposed positions: This high-altitude species tolerates only brief, light frosts; prolonged cold below -5°C, or cold drying winds, will kill exposed growth. In the UK, protect with horticultural fleece and ensure a well-drained root zone to prevent frost-rot.

What creeping gaultheria's hardiness rating actually means

Yes — creeping gaultheria is genuinely cold hardy. Rated RHS H4 and USDA 7-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 7-9 — 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 −10 to −5 °C. Creeping Gaultheria is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for creeping gaultheria as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 creeping gaultheria go outside or overwinter — and where?

Plant it out within USDA 7-9 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 creeping gaultheria can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Frost protection for borderline creeping gaultheria

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

At the cold edge of its range, mulch the root zone in late autumn to buffer the deepest freezes.
Protect container specimens — pots freeze through far faster than open ground, costing roughly a zone of hardiness.
Shelter new growth from late spring frosts with fleece if a hard night is forecast.

Creeping Gaultheria hardiness — frequently asked questions

Is creeping gaultheria cold hardy?

Yes — creeping gaultheria is genuinely cold hardy. Rated RHS H4 and USDA 7-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Creeping Gaultheria is hardy across USDA 7-9; 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 creeping gaultheria can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Creeping Gaultheria is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is creeping gaultheria?

Creeping Gaultheria is rated USDA 7-9 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can creeping gaultheria survive winter outside?

Plant it out within USDA 7-9 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.

How do I protect creeping gaultheria from frost?

At the cold edge of its range, mulch the root zone in late autumn to buffer the deepest freezes. Protect container specimens — pots freeze through far faster than open ground, costing roughly a zone of hardiness. Shelter new growth from late spring frosts with fleece if a hard night is forecast.