Cold hardiness & minimum temperature

Is Monarda 'Jacob Cline' (Monarda didyma 'Jacob Cline')cold hardy? Hardiness zone & min temp

Also called Jacob Cline bee balm.

More about monarda 'jacob cline'

About Monarda 'Jacob Cline'

Monarda didyma 'Jacob Cline' · also called Jacob Cline bee balm · flowering

'Jacob Cline' is a vigorous bee balm cultivar prized for its large, shaggy scarlet-red flowers and strong mildew resistance. An aromatic, mint-family perennial, it draws hummingbirds, bees, and butterflies through midsummer. It forms spreading clumps in moist, fertile soil and full sun, and is one of the most reliable red Monardas for the border.

Cold limit: USDA 4-9 · RHS H7 (-34 to 30°C)

What monarda 'jacob cline''s hardiness rating actually means

Yes — monarda 'jacob cline' is genuinely cold hardy. Rated RHS H7 and USDA 4-9, 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 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 below about −20 °C. Monarda 'Jacob Cline' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for monarda 'jacob cline' 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 monarda 'jacob cline' 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 monarda 'jacob cline' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Monarda 'Jacob Cline' hardiness — frequently asked questions

Is monarda 'jacob cline' cold hardy?

Yes — monarda 'jacob cline' is genuinely cold hardy. Rated RHS H7 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Monarda 'Jacob Cline' 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 monarda 'jacob cline' can survive?

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

What hardiness zone is monarda 'jacob cline'?

Monarda 'Jacob Cline' is rated USDA 4-9 and RHS H7 — Hardy in the severest European continental winters.

Can monarda 'jacob cline' 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 monarda 'jacob cline' 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.