Cold hardiness & minimum temperature

Is Cotoneaster microphyllus (Cotoneaster microphyllus)cold hardy? Hardiness zone & min temp

Also called Littleleaf Cotoneaster, Small-leaved Cotoneaster.

More about cotoneaster microphyllus

About Cotoneaster microphyllus

Cotoneaster microphyllus · also called Littleleaf Cotoneaster, Small-leaved Cotoneaster · flowering

Littleleaf cotoneaster (Cotoneaster microphyllus) is a low, spreading evergreen shrub valued as bonsai for its tiny dark glossy leaves, small white spring flowers and showy red berries. Tough, hardy and quick to ramify, it tolerates pruning and drier spells, performing best in full sun with sharp drainage.

Cold limit: USDA 5-8 (grown outdoors year-round) · RHS H5 (-20 to 30°C)

What cotoneaster microphyllus's hardiness rating actually means

Yes — cotoneaster microphyllus is genuinely cold hardy. Rated RHS H5 and USDA 5-8 (grown outdoors year-round), 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 (grown outdoors year-round) — 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. Cotoneaster microphyllus is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for cotoneaster microphyllus 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 cotoneaster microphyllus go outside or overwinter — and where?

Plant it out within USDA 5-8 (grown outdoors year-round) 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 cotoneaster microphyllus can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Cotoneaster microphyllus hardiness — frequently asked questions

Is cotoneaster microphyllus cold hardy?

Yes — cotoneaster microphyllus is genuinely cold hardy. Rated RHS H5 and USDA 5-8 (grown outdoors year-round), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Cotoneaster microphyllus is hardy across USDA 5-8 (grown outdoors year-round); 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 cotoneaster microphyllus can survive?

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

What hardiness zone is cotoneaster microphyllus?

Cotoneaster microphyllus is rated USDA 5-8 (grown outdoors year-round) and RHS H5 — Hardy in most of the UK and in cold winters.

Can cotoneaster microphyllus survive winter outside?

Plant it out within USDA 5-8 (grown outdoors year-round) 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 cotoneaster microphyllus 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.