Cold hardiness & minimum temperature

Is Daylily 'Rosy Returns' (Hemerocallis 'Rosy Returns')cold hardy? Hardiness zone & min temp

Also called Rosy Returns daylily.

More about daylily 'rosy returns'

About Daylily 'Rosy Returns'

Hemerocallis 'Rosy Returns' · also called Rosy Returns daylily · flowering

Hemerocallis 'Rosy Returns' is a fragrant, reblooming dwarf daylily with rosy-pink flowers and a rose-red eye zone above a lemon-yellow throat. It is one of the most fragrant reblooming daylilies, excellent for borders, edging, and containers. All daylilies are toxic to cats and can cause fatal kidney failure. Avoid planting in areas accessible to cats.

Cold limit: USDA 4-9 · RHS H6 (5-35°C)

What daylily 'rosy returns''s hardiness rating actually means

Yes — daylily 'rosy returns' 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. Daylily 'Rosy Returns' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for daylily 'rosy returns' 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 daylily 'rosy returns' 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 daylily 'rosy returns' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Daylily 'Rosy Returns' hardiness — frequently asked questions

Is daylily 'rosy returns' cold hardy?

Yes — daylily 'rosy returns' 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. Daylily 'Rosy Returns' 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 daylily 'rosy returns' can survive?

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

What hardiness zone is daylily 'rosy returns'?

Daylily 'Rosy Returns' is rated USDA 4-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can daylily 'rosy returns' 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 daylily 'rosy returns' 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.