Cold hardiness & minimum temperature

Is White Mulberry (Morus alba)cold hardy? Hardiness zone & min temp

Also called white mulberry, silkworm mulberry.

More about white mulberry

About White Mulberry

Morus alba · also called white mulberry, silkworm mulberry · edible

Morus alba is a fast-growing, exceptionally hardy deciduous tree historically planted to feed silkworms. It bears sweet white-to-pink (sometimes purple) berries on glossy, variably lobed leaves. Tolerant of poor soil, heat, drought and urban conditions, it fruits heavily in full sun and is among the most adaptable of the edible mulberries.

Cold limit: USDA 4-9 · RHS H6 (-30 to 35C (growing optimum 18-30C))

Watch for — Bleeding sap from pruning: Mulberries bleed heavily if cut in late winter/spring. Prune only when fully dormant in mid-winter or in summer after fruiting to limit sap loss.

What white mulberry's hardiness rating actually means

Yes — white mulberry is genuinely cold hardy. Rated RHS H6 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 4-9 — 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 −20 to −15 °C. White Mulberry is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for white mulberry as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 white mulberry go outside or overwinter — and where?

Plant it out within USDA 4-9 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 white mulberry can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

White Mulberry hardiness — frequently asked questions

Is white mulberry cold hardy?

Yes — white mulberry is genuinely cold hardy. Rated RHS H6 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. White Mulberry is hardy across USDA 4-9; 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 white mulberry can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. White Mulberry is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is white mulberry?

White Mulberry is rated USDA 4-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can white mulberry survive winter outside?

Plant it out within USDA 4-9 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 white mulberry below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.