Repotting guide

When & how to repot Mizuna 'Early Mizuna' (Brassica rapa var. nipposinica 'Early Mizuna')

Also called Early mizuna, Japanese mustard greens.

More about mizuna 'early mizuna'

About Mizuna 'Early Mizuna'

Brassica rapa var. nipposinica 'Early Mizuna' · also called Early mizuna, Japanese mustard greens · edible

'Early Mizuna' is a fast, feathery Japanese mustard green forming a dense rosette of deeply serrated leaves with a mild, peppery tang. Quick from seed and highly cut-and-come-again, it tolerates cool weather and light frost, regrowing repeatedly after cutting. Excellent in salad mixes, stir-fries, and as a baby leaf harvested in as little as three weeks.

Mature size: About 20-30 cm (8-12 inches) tall and up to 30 cm (12 inches) wide; harvest as baby leaf much smaller.

How to tell mizuna 'early mizuna' needs repotting

Repotting on a calendar is less reliable than reading the plant. For mizuna 'early mizuna', watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot mizuna 'early mizuna' on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot mizuna 'early mizuna'

Pot on seedlings as they grow; not a perennial repot. Mizuna 'Early Mizuna'is grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Mounded rosette of finely divided, feathery green leaves on thin white stalks; a biennial grown as an annual that bolts to a flower stalk in heat or long days..

What size pot to step mizuna 'early mizuna' up to

Pot mizuna 'early mizuna' on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot mizuna 'early mizuna'

Pot mizuna 'early mizuna' on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting mizuna 'early mizuna'

Pot on before it is root-bound. Check mizuna 'early mizuna' regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh fertile, moisture-retentive loam at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water mizuna 'early mizuna' in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for mizuna 'early mizuna'

Mizuna 'Early Mizuna' wants fertile, moisture-retentive loam. Rich in organic matter with good drainage, pH 6.0-7.0. Light, free-draining soils with added compost suit its rapid leafy growth and frequent cutting. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting mizuna 'early mizuna' — frequently asked questions

How often should you repot mizuna 'early mizuna'?

Pot on seedlings as they grow; not a perennial repot for mizuna 'early mizuna'. Mizuna 'Early Mizuna' is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into fertile, moisture-retentive loam so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does mizuna 'early mizuna' need?

When is the best time of year to repot mizuna 'early mizuna'?

Can you put mizuna 'early mizuna' straight into a much bigger pot?

No. Even a fast-growing mizuna 'early mizuna' should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise mizuna 'early mizuna' after repotting?

Not immediately. Wait about 1 week after repotting mizuna 'early mizuna'. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.