Cold hardiness & minimum temperature

Is Rosemary-Leaved Rock Rose (Cistus libanotis)cold hardy? Hardiness zone & min temp

Also called Rosemary-leaved rock rose, Libanotis rock rose.

More about rosemary-leaved rock rose

About Rosemary-Leaved Rock Rose

Cistus libanotis · also called Rosemary-leaved rock rose, Libanotis rock rose · flowering

Cistus libanotis is a compact evergreen shrub native to the southwestern Iberian Peninsula — southern Portugal and south-west Spain — where it grows on dry, sandy coastal heathlands and scrub. It produces abundant small white flowers from late spring to midsummer and thrives in full sun with very free-draining, poor to moderately fertile soil; established plants are highly drought-tolerant and should never be overwatered. The single most important care fact is that it resents hard pruning, so only light shaping immediately after flowering is advised. Cistus is not listed on the ASPCA Toxic and Non-Toxic Plants database; as the genus is not confirmed non-toxic, treat as mildly toxic and keep pets away as a precaution.

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

Watch for — Frost damage: Cold, wet winters can cause die-back of shoots and, in severe frosts below -5°C (23°F), loss of the whole plant. Plant in a sheltered south- or west-facing spot and avoid frost pockets.

What rosemary-leaved rock rose's hardiness rating actually means

Yes — rosemary-leaved rock rose 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. Rosemary-Leaved Rock Rose is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for rosemary-leaved rock rose 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 rosemary-leaved rock rose 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 rosemary-leaved rock rose can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Rosemary-Leaved Rock Rose hardiness — frequently asked questions

Is rosemary-leaved rock rose cold hardy?

Yes — rosemary-leaved rock rose 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. Rosemary-Leaved Rock Rose 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 rosemary-leaved rock rose can survive?

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

What hardiness zone is rosemary-leaved rock rose?

Rosemary-Leaved Rock Rose is rated USDA 8-10 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can rosemary-leaved rock rose 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 rosemary-leaved rock rose 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.