Cold hardiness & minimum temperature

Is Canada Mayflower (Maianthemum canadense)cold hardy? Hardiness zone & min temp

Also called Canada Mayflower, Wild Lily of the Valley, False Lily of the Valley, Two-leaved Solomon's Seal.

More about canada mayflower

About Canada Mayflower

Maianthemum canadense · also called Canada Mayflower, Wild Lily of the Valley · flowering

Canada Mayflower is a low-growing North American woodland groundcover producing small, glossy heart-shaped leaves and tiny fragrant white flowers in late spring, followed by speckled red berries. It spreads steadily via slender rhizomes to form a lush carpet in acidic, shaded woodland gardens, thriving in cool, moist conditions.

Cold limit: USDA 2–7 · RHS H7 (-5–22°C)

What canada mayflower's hardiness rating actually means

Yes — canada mayflower is genuinely cold hardy. Rated RHS H7 and USDA 2–7, 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 2–7 — 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. Canada Mayflower is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for canada mayflower 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 canada mayflower go outside or overwinter — and where?

Plant it out within USDA 2–7 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 canada mayflower can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Canada Mayflower hardiness — frequently asked questions

Is canada mayflower cold hardy?

Yes — canada mayflower is genuinely cold hardy. Rated RHS H7 and USDA 2–7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Canada Mayflower is hardy across USDA 2–7; 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 canada mayflower can survive?

Minimum survivable temperature is roughly below about −20 °C. Canada Mayflower is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is canada mayflower?

Canada Mayflower is rated USDA 2–7 and RHS H7 — Hardy in the severest European continental winters.

Can canada mayflower survive winter outside?

Plant it out within USDA 2–7 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 canada mayflower 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.