Cold hardiness & minimum temperature

Is Missouri Coneflower (Rudbeckia missouriensis)cold hardy? Hardiness zone & min temp

Also called Missouri Coneflower, Missouri Black-eyed Susan.

More about missouri coneflower

About Missouri Coneflower

Rudbeckia missouriensis · also called Missouri Coneflower, Missouri Black-eyed Susan · flowering

Rudbeckia missouriensis is a long-lived native perennial endemic to the limestone glades and rocky Ozark prairies of Missouri and adjacent states, producing masses of golden-yellow daisy flowers with dark brown central cones on branched, hairy stems from June through October. One of the most drought-tolerant rudbeckias, it thrives in dry, shallow, rocky soils over limestone or dolomite substrates and full sun, making it an outstanding choice for xeriscape, rock gardens, and native prairie plantings. It is notably more compact and less aggressive than many relatives. Rudbeckia is not individually confirmed safe on the ASPCA database; treat with caution around pets.

Cold limit: USDA 5–8 · RHS H6 (−28°C to 38°C)

What missouri coneflower's hardiness rating actually means

Yes — missouri coneflower is genuinely cold hardy. Rated RHS H6 and USDA 5–8, 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 5–8 — 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. Missouri Coneflower is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for missouri coneflower 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 missouri coneflower go outside or overwinter — and where?

Plant it out within USDA 5–8 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 missouri coneflower can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Missouri Coneflower hardiness — frequently asked questions

Is missouri coneflower cold hardy?

Yes — missouri coneflower is genuinely cold hardy. Rated RHS H6 and USDA 5–8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Missouri Coneflower is hardy across USDA 5–8; 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 missouri coneflower can survive?

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

What hardiness zone is missouri coneflower?

Missouri Coneflower is rated USDA 5–8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can missouri coneflower survive winter outside?

Plant it out within USDA 5–8 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 missouri coneflower 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.