Cold hardiness & minimum temperature

Is Lemon Bee Balm (Monarda citriodora)cold hardy? Hardiness zone & min temp

Also called Lemon Bee Balm, Lemon Mint, Purple Horsemint.

More about lemon bee balm

About Lemon Bee Balm

Monarda citriodora · also called Lemon Bee Balm, Lemon Mint · herb

Lemon bee balm is a fast, easy annual or short-lived perennial with citrus-scented foliage and tiered whorls of lavender-pink, spotted tubular flowers. A magnet for bees, butterflies and hummingbirds, it self-seeds freely in sunny, well-drained spots. More drought-tolerant than perennial bee balms, this North American native suits wildflower plantings, herb gardens and pollinator borders with minimal fuss.

Cold limit: USDA 2-11 (usually grown as an annual or short-lived perennial; self-seeds readily) · RHS H4 (-12 to 32°C)

What lemon bee balm's hardiness rating actually means

Hardiness works differently for lemon bee balm: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 2-11 (usually grown as an annual or short-lived perennial; self-seeds readily) — 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

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for lemon bee balm as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can lemon bee balm go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

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 lemon bee balm can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Frost protection for borderline lemon bee balm

Lemon Bee Balm is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Lemon Bee Balm hardiness — frequently asked questions

Is lemon bee balm cold hardy?

Hardiness works differently for lemon bee balm: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Lemon Bee Balm is grown 2-11 (usually grown as an annual or short-lived perennial; self-seeds readily); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature lemon bee balm can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is lemon bee balm?

Lemon Bee Balm is rated USDA 2-11 (usually grown as an annual or short-lived perennial; self-seeds readily) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can lemon bee balm survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect lemon bee balm from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.