Cold hardiness & minimum temperature

Is Tat Soi 'Yukina Savoy' (Brassica rapa var. narinosa 'Yukina Savoy')cold hardy? Hardiness zone & min temp

Also called Yukina Savoy, savoy tatsoi, Japanese savoy mustard.

More about tat soi 'yukina savoy'

About Tat Soi 'Yukina Savoy'

Brassica rapa var. narinosa 'Yukina Savoy' · also called Yukina Savoy, savoy tatsoi · edible

'Yukina Savoy' is an upright, cold-hardy Asian green, a heat-tolerant tatsoi type with thick, blistered (savoyed) dark-green leaves on pale stems. Mild and slightly mustardy, it crops fast in cool weather, resists bolting better than flat tatsoi, and sweetens after light frost. Harvest as cut-and-come-again baby leaf or as full rosettes.

Cold limit: USDA 2-11 (grown as a cool-season annual) · RHS H5 (10-22°C)

What tat soi 'yukina savoy''s hardiness rating actually means

Hardiness works differently for tat soi 'yukina savoy': 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 H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 2-11 (grown as a cool-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 tat soi 'yukina savoy' 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 tat soi 'yukina savoy' 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 tat soi 'yukina savoy' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Frost protection for borderline tat soi 'yukina savoy'

Tat Soi 'Yukina Savoy' 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.

Tat Soi 'Yukina Savoy' hardiness — frequently asked questions

Is tat soi 'yukina savoy' cold hardy?

Hardiness works differently for tat soi 'yukina savoy': 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. Tat Soi 'Yukina Savoy' is grown 2-11 (grown as a cool-season annual); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature tat soi 'yukina savoy' 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 tat soi 'yukina savoy'?

Tat Soi 'Yukina Savoy' is rated USDA 2-11 (grown as a cool-season annual) and RHS H5 — Hardy in most of the UK and in cold winters.

Can tat soi 'yukina savoy' 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 tat soi 'yukina savoy' 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.