How to Grow Mibunas UK

By the SoilCommander Editorial Team, under the guidance of Nitin Sharma, Co-Founder · · How we check our facts

On this page
  1. Mibuna (Brassica rapa var. japonica)
  2. When to Plant Mibunas in the UK
  3. Quick Facts
  4. At a Glance
  5. Soil & Growing Conditions
  6. Growth Stages
  7. Harvest & Storage
  8. Diseases
  9. Pests
  10. Mibuna, Prized for its Narrow, Smooth-Edged Leaves
  11. Plan your Mibunas planting
  12. Growing Mibuna in another region
  13. References
  14. Frequently Asked Questions

In the UK, mibuna goes in the ground early March to late August.

Timing is the decision that matters most in the UK: sowing early March, and that same window applies across all 4 regions covered here.

The short answer

Plant
Early March to late August
Site
soil pH 6–7.5
Biggest risk
Club root

Core growing advice on this page is checked against named horticultural sources — see References.

Mibuna (Brassica rapa var. japonica)

Mibuna rosette of narrow, entire-margin leaves — “Mibuna” by Kingfiser is licensed under CC BY-SA 4.0.

1 sources cited · Single source

When to Plant Mibunas in the UK

When to plant mibunas in the UK: in Southern England, sow early March to late August. Find your area in the table below.

Mibuna growing with its distinctive narrow, smooth-edged leaves — “Brassica rapa subsp. japonica (Mibuna), growing rosette with narrow entire leaves (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF
“Brassica rapa subsp. japonica (Mibuna), growing rosette with narrow entire leaves (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF.
Region Sow
Southern England early March to late August
Midlands early March to late August
Northern England early March to late August
Scotland early March to late August
Southern England - detail & sources

RHS: outdoor sowing March to August, with no UK-region-specific dates given; this window is applied across all four sub-regions rather than inventing a north/south gradient the source does not support.

Midlands - detail & sources

RHS: outdoor sowing March to August, with no UK-region-specific dates given; this window is applied across all four sub-regions rather than inventing a north/south gradient the source does not support.

Northern England - detail & sources

RHS: outdoor sowing March to August, with no UK-region-specific dates given; this window is applied across all four sub-regions rather than inventing a north/south gradient the source does not support.

Scotland - detail & sources

RHS: outdoor sowing March to August, with no UK-region-specific dates given; this window is applied across all four sub-regions rather than inventing a north/south gradient the source does not support.

A page from the UK Vegetable Garden Planner PDF: the crop rotation planner, with a planning grid and four-bed rotation tips

Plan your mibuna — and the rest of the plot

This page covers mibuna. For every crop's sowing months on one chart, use the free UK vegetable planting calendar, and browse the UK vegetable growing guides for what else to grow alongside it. When you want the whole season on paper, the UK Vegetable Garden Planner is a printable PDF:

  • Twelve month-by-month sowing and harvest spreads
  • Raised bed, allotment and container layout pages for your own plot
  • A four-year crop rotation planner
  • Seed inventory, sowing log and harvest tracker
See inside the UK Vegetable Garden Planner →

Instant PDF download · reprint every season

Quick Facts

Mibuna rosette of narrow, entire-margin leaves — “Mibuna” by Kingfiser is licensed under CC BY-SA 4.0.
“Mibuna” by Kingfiser is licensed under CC BY-SA 4.0.
Factor Value
Soil pH 6 - 7.5
Soil texture fork in compost or well-rotted manure (RHS)
Drainage well-drained
Lifecycle annual or biennial grown as an annual
Edible parts leaves

At a Glance

A clump of Mibuna with reddish stem bases — “Brassica rapa subsp. japonica (Mibuna), clump with reddish stem bases (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF
“Brassica rapa subsp. japonica (Mibuna), clump with reddish stem bases (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF.
Brassica rapa var. japo… Mibuna Club root Cabbage caterpillars Flea beetles Pigeons Snails Slugs DISEASES PESTS

Soil & Growing Conditions

A clump of Mibuna with reddish stem bases — “Brassica rapa subsp. japonica (Mibuna), clump with reddish stem bases (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF
“Brassica rapa subsp. japonica (Mibuna), clump with reddish stem bases (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF.

Water: moist soil required to perform well (RHS)

Soil pH range

6 7.5

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Growth Stages

Mibuna and Mizuna leaves side by side, showing the difference in leaf shape — “Mibuna and Mizuna” by Kingfiser is licensed under CC BY-SA 4.0.
“Mibuna and Mizuna” by Kingfiser is licensed under CC BY-SA 4.0.
Stage BBCH Notes
Sowing 0 Sow 1cm deep in shallow drills, rows 23cm apart; germinates in about a week (RHS).
Thinning 1 Thin to 10-15cm for salad leaves, 20cm for larger leaves, 30-40cm for mature plants (RHS).
Leaf growth 3 Baby leaves reach 8-10cm tall about a month after sowing; keep soil moist to prevent bolting (RHS).
Cut-and-come-again harvest 8 Whole rosettes can be cut after 6-8 weeks, about 5cm above ground, to allow re-sprouting (RHS).

Harvest & Storage

A harvested bundle of Mibuna leaves with roots attached — “Brassica rapa subsp. japonica (Mibuna), harvested bundle with roots (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF
“Brassica rapa subsp. japonica (Mibuna), harvested bundle with roots (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF.

When to pick: Harvest baby leaves once 8-10cm tall, about a month after sowing, cut-and-come-again for repeated picking; or cut whole rosettes after 6-8 weeks about 5cm above ground to allow re-sprouting (RHS).

Diseases

Mibuna rosette of narrow, entire-margin leaves — “Mibuna” by Kingfiser is licensed under CC BY-SA 4.0.
“Mibuna” by Kingfiser is licensed under CC BY-SA 4.0.
moderate

Plasmodiophora brassicae

Likely rather than confirmed: no source names this crop directly, but it shares a species (Brassica rapa) with Mizuna, which is susceptible to this disease.

Pests

Mibuna growing with its distinctive narrow, smooth-edged leaves — “Brassica rapa subsp. japonica (Mibuna), growing rosette with narrow entire leaves (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF
“Brassica rapa subsp. japonica (Mibuna), growing rosette with narrow entire leaves (Barstow garden collection)” by Stephen Barstow is licensed under CC BY 4.0. Source: GBIF.
Cabbage caterpillars
moderate

Pieris brassicae; Pieris rapae; Pieris napi; Mamestra brassicae; Plutella xylostella

RHS names this directly: cabbage caterpillars.

Flea beetles
low

Chrysomelidae: Alticini (various spp.)

RHS names this directly: flea beetles, though damage is cosmetic only.

Pigeons
moderate

Columbidae (family)

RHS names this directly: pigeons.

Snails
low

Gastropoda (snails, various spp.)

RHS names this directly: snails.

Slugs
low

Gastropoda (slugs, various spp.)

RHS names this directly: slugs.

Plan your Mibunas planting

When to sow and plant Mibunas depends on your own frost dates. Check the UK vegetable planting calendar. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.

Growing Mibuna in another region

Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.

References

  1. Mibuna forms larger, denser clumps of narrower, dark green, smooth-edged leaves with a light mustard flavour, distinct from Mizuna's more deeply lobed leaves -- suitable for salads or light cooking. Grows best in cool, damp weather of spring and autumn, tolerates semi-shade, requires moist soil; container minimum 30cm wide. Soil prep: fork in compost or well-rotted manure to retain moisture, tread and rake to fine texture. Sow 1cm deep in shallow drills, rows 23cm apart, plants thinned to 10-15cm for salad leaves, 20cm for larger leaves, 30-40cm for mature plants; germinates in about a week; outdoor sowing March-August. Harvest baby leaves once 8-10cm tall (about a month); cut-and-come-again for multiple pickings, or harvest whole rosettes after 6-8 weeks, cutting 5cm above ground for re-sprouting. Bolts in hot, dry conditions. Pests: slugs, snails, flea beetles (cosmetic damage), cabbage caterpillars, pigeons. Prevention: keep soil moist, mulch, insect-proof mesh, regular weeding.

1 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.

Frequently Asked Questions

When should I sow mibuna in the UK?

In Southern England, from early March. In Scotland, wait until early March. Treat these as a guide rather than a fixed date — the governing rule is to sow only once frost risk has passed and temperatures are reliably warm enough.

When do I sow mibuna?

Sow early March to late August.

What soil pH does mibuna need?

A pH of about 6–7.5. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.

What problems affect mibuna?

Our data links 1 disease and 5 pests to this crop. See the sections above for each one and how to manage it.

Plan next season before the problems start

Most of the advice on this page comes down to timing and spacing — sowing at the right moment, rotating beds, and giving plants enough airflow. The UK Garden Planner lays your plot out month by month so those decisions are already made before the season starts.

Get the UK Garden Planner →

Instant PDF download · Written for UK growing conditions

SoilCommander Editorial Team — under the guidance of Nitin Sharma, Co-Founder

Every growing guide is checked against RHS, USDA Cooperative Extension, and other named horticultural authorities before publishing. How we check our facts.

How this guide is put together

The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against RHS and Met Office guidance. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.

Vegetable Growing Guides UK

Crops With the Same Problems

Related Problem Guides

Last verified 2026-08-29

Plan Mibunas by month

The months this guide gives for sowing or planting, each with the full list of jobs for that month in the UK:

More from the same group (brassicas & mustards):

Relevant next steps

Where To Go From Here

Take this crop from reading into a written plan for your own beds.

UK garden plannerTurn this crop guide into sowing dates, bed layouts and a harvest record. All growing guidesBrowse every crop we cover for your region, A to Z. Planting CalendarSee how this crop fits alongside everything else you are growing.

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