Cold hardiness & minimum temperature

Is Chrysanthemum 'Snowdon' (Chrysanthemum 'Snowdon')cold hardy? Hardiness zone & min temp

Also called Snowdon mum, white chrysanthemum, hardy mum.

More about chrysanthemum 'snowdon'

About Chrysanthemum 'Snowdon'

Chrysanthemum 'Snowdon' · also called Snowdon mum, white chrysanthemum · flowering

A classic white-flowered garden chrysanthemum with neat, fully double blooms on sturdy upright stems, flowering in late summer and autumn. Excellent as a cut flower and border specimen. Toxic to cats, dogs, and horses. Named after the highest peak in Wales, it is popular in British autumn gardens.

Cold limit: USDA 5-9 · RHS H5 (4-22°C)

Watch for — Winter crown rot: Caused by wet, poorly drained soil; mulch crowns in autumn and ensure drainage is sharp.

What chrysanthemum 'snowdon''s hardiness rating actually means

Yes — chrysanthemum 'snowdon' 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. Chrysanthemum 'Snowdon' is built for winter — once established it takes hard frost and snow in its stride.

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

Chrysanthemum 'Snowdon' hardiness — frequently asked questions

Is chrysanthemum 'snowdon' cold hardy?

Yes — chrysanthemum 'snowdon' 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. Chrysanthemum 'Snowdon' 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 chrysanthemum 'snowdon' can survive?

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

What hardiness zone is chrysanthemum 'snowdon'?

Chrysanthemum 'Snowdon' is rated USDA 5-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can chrysanthemum 'snowdon' 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 chrysanthemum 'snowdon' 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.