Cold hardiness & minimum temperature

Is Shagbark manzanita (Arctostaphylos tomentosa)cold hardy? Hardiness zone & min temp

Also called Shagbark manzanita, Woolly manzanita.

More about shagbark manzanita

About Shagbark manzanita

Arctostaphylos tomentosa · also called Shagbark manzanita, Woolly manzanita · flowering

Shagbark manzanita is a drought-tolerant California native shrub with shredding reddish-brown bark, woolly stems, and clusters of white to pale-pink urn-shaped flowers in late winter. It thrives in full sun, fast-draining acidic soil, and is highly fire-resistant once established. Ideal for Mediterranean-climate gardens with minimal irrigation.

Cold limit: USDA 8-10 · RHS H4 (−5 to 35°C)

What shagbark manzanita's hardiness rating actually means

Yes — shagbark manzanita is genuinely cold hardy. Rated RHS H4 and USDA 8-10, 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 8-10 — 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

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

Concretely, for shagbark manzanita 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 shagbark manzanita go outside or overwinter — and where?

Plant it out within USDA 8-10 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 shagbark manzanita can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Shagbark manzanita hardiness — frequently asked questions

Is shagbark manzanita cold hardy?

Yes — shagbark manzanita is genuinely cold hardy. Rated RHS H4 and USDA 8-10, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Shagbark manzanita is hardy across USDA 8-10; 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 shagbark manzanita can survive?

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

What hardiness zone is shagbark manzanita?

Shagbark manzanita is rated USDA 8-10 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can shagbark manzanita survive winter outside?

Plant it out within USDA 8-10 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 shagbark manzanita below its minimum temperature?

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.