How to Grow Mibunas | Care, Pests & Disease Control

Diseases

Club root

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

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.

Quick Facts

Factor	Value
Soil pH	6 - 7.5
Sunlight	3-3 hours direct sun
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

Soil & Growing Conditions

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

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

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).

Mibuna, Prized for its Narrow, Smooth-Edged Leaves

Narrower, smooth-edged leaves

RHS: Mibuna forms larger, denser clumps of narrower, dark green, smooth-edged leaves with a light mustard flavour.

Easily confused with Mizuna

RHS treats Mibuna and Mizuna as genuinely distinct named varieties -- Mizuna's leaves are more deeply lobed and feathery by comparison, visible side by side here.

Grows best in cool, damp weather

RHS: grows best in the cool, damp weather of spring and autumn, tolerating semi-shade, and needs moist soil to perform well.

A dense, quick-growing clump

RHS: sow 1cm deep in shallow drills; seedlings germinate in about a week and can be thinned for successive harvests.

Cut-and-come-again harvest

RHS: harvest baby leaves once 8-10cm tall for cut-and-come-again pickings, or take whole rosettes after 6-8 weeks, cutting 5cm above ground to allow re-sprouting.

References

1. Royal Horticultural Society - How to grow mizuna and mibuna

   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.