Cold hardiness & minimum temperature

Is Great Solomon's Seal (Polygonatum commutatum)cold hardy? Hardiness zone & min temp

Also called Great Solomon's Seal, Giant Solomon's Seal, Smooth Great Solomon's Seal.

More about great solomon's seal

About Great Solomon's Seal

Polygonatum commutatum · also called Great Solomon's Seal, Giant Solomon's Seal · flowering

The giant of the Solomon's seal genus, producing statuesque arching stems up to 2 m tall with large oval leaves and clusters of 2-8 pendulous greenish-white bells in late spring. Native to moist, rich lowland woods of central and eastern North America. Dramatic accent for large shade gardens and woodland borders. Hardy to USDA zone 3.

Cold limit: USDA 3-9 · RHS H7 (-40°C to 28°C)

What great solomon's seal's hardiness rating actually means

Yes — great solomon's seal is genuinely cold hardy. Rated RHS H7 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 3-9 — 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 below about −20 °C. Great Solomon's Seal is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for great solomon's seal as it gets too cold:

It tolerates winter lows to about −20 °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 great solomon's seal go outside or overwinter — and where?

Plant it out within USDA 3-9 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 great solomon's seal can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Great Solomon's Seal hardiness — frequently asked questions

Is great solomon's seal cold hardy?

Yes — great solomon's seal is genuinely cold hardy. Rated RHS H7 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Great Solomon's Seal is hardy across USDA 3-9; 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 great solomon's seal can survive?

Minimum survivable temperature is roughly below about −20 °C. Great Solomon's Seal is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is great solomon's seal?

Great Solomon's Seal is rated USDA 3-9 and RHS H7 — Hardy in the severest European continental winters.

Can great solomon's seal survive winter outside?

Plant it out within USDA 3-9 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 great solomon's seal below its minimum temperature?

It tolerates winter lows to about −20 °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.