Cold hardiness & minimum temperature

Is Climbing French Bean (Phaseolus vulgaris 'Blue Lake Climbing')cold hardy? Hardiness zone & min temp

Also called Blue Lake bean, climbing French bean, pole bean.

More about climbing french bean

About Climbing French Bean

Phaseolus vulgaris 'Blue Lake Climbing' · also called Blue Lake bean, climbing French bean · edible

'Blue Lake' is a heavy-cropping climbing French bean producing long, round, stringless green pods over a long season. A frost-tender annual, it twines up canes or netting to 2 m and crops more per square metre than dwarf types. Pick young and often, and the more you harvest the more pods the plant sets.

Cold limit: USDA 2-11 (warm-season annual) · RHS H2 (16-30°C)

Watch for — Flower drop: Dry soil or cold snaps cause flowers to fall without setting pods; keep watering even and avoid planting out too early.

What climbing french bean's hardiness rating actually means

Hardiness works differently for climbing french bean: 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 H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 2-11 (warm-season annual) — 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 climbing french bean 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 climbing french bean 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 climbing french bean can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline climbing french bean

Climbing French Bean 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.

Climbing French Bean hardiness — frequently asked questions

Is climbing french bean cold hardy?

Hardiness works differently for climbing french bean: 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. Climbing French Bean is grown 2-11 (warm-season annual); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature climbing french bean 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 climbing french bean?

Climbing French Bean is rated USDA 2-11 (warm-season annual) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can climbing french bean 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 climbing french bean 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.