Cold hardiness & minimum temperature

Is Grosso Lavender (Lavandula × intermedia 'Grosso')cold hardy? Hardiness zone & min temp

Also called Lavandin.

More about grosso lavender

About Grosso Lavender

Lavandula × intermedia 'Grosso' · also called Lavandin · herb

'Grosso' is the world's most widely grown lavandin, a sterile English-x-Portuguese hybrid bred for high oil yield and long, fragrant violet wands. It is larger, more vigorous, and more disease-resistant than English lavender, blooming in mid-to-late summer. It demands full sun and sharp drainage and dislikes humidity and rich, wet soil.

Cold limit: USDA 5-9 · RHS H5 (10-30°C)

Watch for — Root rot and winter wet: Heavy or soggy soil rots the crown. Plant on a slope or raised gritty bed and avoid irrigation in cold, damp months.

What grosso lavender's hardiness rating actually means

Yes — grosso lavender is genuinely cold hardy. Rated RHS H5 and USDA 5-9, 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 5-9 — 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. Grosso Lavender is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 5-9 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 grosso lavender can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Grosso Lavender hardiness — frequently asked questions

Is grosso lavender cold hardy?

Yes — grosso lavender is genuinely cold hardy. Rated RHS H5 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Grosso Lavender is hardy across USDA 5-9; 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 grosso lavender can survive?

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

What hardiness zone is grosso lavender?

Grosso Lavender is rated USDA 5-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can grosso lavender survive winter outside?

Plant it out within USDA 5-9 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 grosso 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.