Cold hardiness & minimum temperature

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

Also called Red Hot Returns daylily.

More about daylily 'red hot returns'

About Daylily 'Red Hot Returns'

Hemerocallis 'Red Hot Returns' · also called Red Hot Returns daylily · flowering

Hemerocallis 'Red Hot Returns' is a vigorous, reblooming daylily with brilliant cherry-red flowers and a contrasting yellow-green throat. It delivers multiple waves of colour from early summer well into autumn. All daylilies are extremely toxic to cats and can cause fatal kidney failure. Unsuitable for any garden where cats have access.

Cold limit: USDA 3-9 · RHS H6 (5-35°C)

What daylily 'red hot returns''s hardiness rating actually means

Yes — daylily 'red hot returns' is genuinely cold hardy. Rated RHS H6 and USDA 3-9, 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 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 about −20 to −15 °C. Daylily 'Red Hot Returns' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for daylily 'red hot 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 'red hot returns' 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 daylily 'red hot 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 'Red Hot Returns' hardiness — frequently asked questions

Is daylily 'red hot returns' cold hardy?

Yes — daylily 'red hot returns' is genuinely cold hardy. Rated RHS H6 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Daylily 'Red Hot Returns' 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 daylily 'red hot returns' can survive?

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

What hardiness zone is daylily 'red hot returns'?

Daylily 'Red Hot Returns' is rated USDA 3-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can daylily 'red hot returns' 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 daylily 'red hot 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.