Cold hardiness & minimum temperature

Is Sierra Leucothoe (Leucothoe davisiae)cold hardy? Hardiness zone & min temp

Also called Sierra Leucothoe, Sierra Laurel, Western Leucothoe.

More about sierra leucothoe

About Sierra Leucothoe

Leucothoe davisiae · also called Sierra Leucothoe, Sierra Laurel · flowering

Leucothoe davisiae is a compact, slow-growing broadleaf evergreen shrub native to bogs and wet streambanks in the Sierra Nevada, Klamath Mountains, and southern Oregon at high elevation. It produces erect, fragrant white flower racemes in May and holds neat, glossy green foliage year-round — making it an excellent foil for other acid-loving shrubs. Consistent moisture and acidic soil are non-negotiable; it will not persist in dry conditions. Toxic to dogs, cats, and horses via grayanotoxins.

Cold limit: USDA 5-8 · RHS H5 (-20 to 28°C)

What sierra leucothoe's hardiness rating actually means

Yes — sierra leucothoe is genuinely cold hardy. Rated RHS H5 and USDA 5-8, 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 5-8 — 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 about −15 to −10 °C. Sierra Leucothoe is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sierra leucothoe 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 sierra leucothoe go outside or overwinter — and where?

Plant it out within USDA 5-8 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 sierra leucothoe can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Sierra Leucothoe hardiness — frequently asked questions

Is sierra leucothoe cold hardy?

Yes — sierra leucothoe is genuinely cold hardy. Rated RHS H5 and USDA 5-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Sierra Leucothoe is hardy across USDA 5-8; 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 sierra leucothoe can survive?

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

What hardiness zone is sierra leucothoe?

Sierra Leucothoe is rated USDA 5-8 and RHS H5 — Hardy in most of the UK and in cold winters.

Can sierra leucothoe survive winter outside?

Plant it out within USDA 5-8 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 sierra leucothoe 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.