Cold hardiness & minimum temperature

Is Grosso lavandin (Lavandula x intermedia 'Grosso')cold hardy? Hardiness zone & min temp

Also called Grosso lavandin, Fat Spike lavender, Grosso lavender.

More about grosso lavandin

About Grosso lavandin

Lavandula x intermedia 'Grosso' · also called Grosso lavandin, Fat Spike lavender · herb

The world's most commercially grown lavender cultivar, 'Grosso' dominates the essential-oil industry of Provence with its exceptionally large, fat, deep-violet flower spikes and very high linalool oil yield. A vigorous, long-lived lavandin with a strongly sweet-camphor fragrance, it makes a magnificent garden plant for large borders, lavender fields, and dried-flower harvest.

Cold limit: USDA 5–8 · RHS H5 (-15 to 40°C)

What grosso lavandin's hardiness rating actually means

Yes — grosso lavandin 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. Grosso lavandin is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for grosso lavandin 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 lavandin 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 grosso lavandin can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Grosso lavandin hardiness — frequently asked questions

Is grosso lavandin cold hardy?

Yes — grosso lavandin 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. Grosso lavandin 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 grosso lavandin can survive?

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

What hardiness zone is grosso lavandin?

Grosso lavandin is rated USDA 5–8 and RHS H5 — Hardy in most of the UK and in cold winters.

Can grosso lavandin 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 grosso lavandin 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.