Cold hardiness & minimum temperature

Is Creeping Mazus (Mazus reptans)cold hardy? Hardiness zone & min temp

Also called Creeping Mazus, Chinese Marshflower.

More about creeping mazus

About Creeping Mazus

Mazus reptans · also called Creeping Mazus, Chinese Marshflower · flowering

A fast-spreading, low-growing perennial producing masses of small, snapdragon-like lavender-blue flowers with white and yellow markings from late spring to early summer. Grows only 2–5 cm tall, tolerates light foot traffic, and fills gaps between stepping stones effectively. Prefers moist conditions and can be used in rain gardens. Not individually listed by ASPCA.

Cold limit: USDA 5–8 · RHS H5 (-15–25°C)

Watch for — Winter dieback in cold zones: In USDA zone 5, the mat may die back partially or fully in harsh winters. Protect with a light covering of dry mulch or evergreen branches over winter; the crown usually re-sprouts reliably in spring.

What creeping mazus's hardiness rating actually means

Yes — creeping mazus 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. Creeping Mazus is built for winter — once established it takes hard frost and snow in its stride.

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

Creeping Mazus hardiness — frequently asked questions

Is creeping mazus cold hardy?

Yes — creeping mazus 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. Creeping Mazus 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 creeping mazus can survive?

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

What hardiness zone is creeping mazus?

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

Can creeping mazus 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 creeping mazus 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.