Cold hardiness & minimum temperature

Is Naples Cotton Lavender (Santolina neapolitana)cold hardy? Hardiness zone & min temp

Also called Naples cotton lavender, Rosemary-leaved lavender cotton, Naples santolina.

More about naples cotton lavender

About Naples Cotton Lavender

Santolina neapolitana · also called Naples cotton lavender, Rosemary-leaved lavender cotton · herb

Santolina neapolitana is an evergreen sub-shrub native to the calcareous hills of southwestern Italy (Campania region), closely related to Santolina pinnata and sometimes treated as a subspecies of it. It produces feathery, aromatic, pale grey-green foliage and bright lemon-yellow, button-like flowerheads 2 cm across in summer, borne on long wiry stalks well above the foliage. The RHS has awarded it the Award of Garden Merit, recognising its reliable garden performance in well-drained, sunny positions. Santolina is not listed on the ASPCA database; treat as mildly toxic to cats and dogs.

Cold limit: USDA 6-9 · RHS H5 (-15°C to 35°C)

What naples cotton lavender's hardiness rating actually means

Yes — naples cotton lavender is genuinely cold hardy. Rated RHS H5 and USDA 6-9, 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 6-9 — 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 −15 to −10 °C. Naples Cotton Lavender is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for naples cotton lavender 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 naples cotton lavender go outside or overwinter — and where?

Plant it out within USDA 6-9 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 naples cotton lavender can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Naples Cotton Lavender hardiness — frequently asked questions

Is naples cotton lavender cold hardy?

Yes — naples cotton lavender is genuinely cold hardy. Rated RHS H5 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Naples Cotton Lavender is hardy across USDA 6-9; 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 naples cotton lavender can survive?

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

What hardiness zone is naples cotton lavender?

Naples Cotton Lavender is rated USDA 6-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can naples cotton lavender survive winter outside?

Plant it out within USDA 6-9 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.

What happens to naples cotton lavender 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.