Repotting guide

When & how to repot Daikon Radish (Raphanus sativus var. longipinnatus)

Also called Mooli, White radish, Japanese radish.

More about daikon radish

About Daikon Radish

Raphanus sativus var. longipinnatus · also called Mooli, White radish · edible

Daikon is a large East Asian radish producing long white roots, often 30 cm or more, with a mild, sweet-peppery flavour. A cool-season crop best sown in late summer for autumn harvest, it needs deeply worked soil for its size and 50-70 days to mature. Its deep taproot also makes it a popular soil-breaking cover crop.

Mature size: Roots commonly 20-45 cm (8-18 in) long and 5-8 cm (2-3 in) thick; leafy tops 30-50 cm (12-20 in) tall.

Watch for — Forked or stunted roots: Stones, compacted soil, hard pans, or fresh manure cause the long roots to fork and stunt. Double-dig deeply and clear stones before sowing.

How to tell daikon radish needs repotting

Repotting on a calendar is less reliable than reading the plant. For daikon radish, 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 daikon radish 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 daikon radish

Pot on seedlings as they grow; not a perennial repot. Daikon Radishis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Large rosette of deeply lobed green leaves above a long, tapering or cylindrical white taproot that often pushes well above the soil line. A biennial grown as an annual; bolts under heat and long-day stress..

What size pot to step daikon radish up to

Pot daikon radish 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 daikon radish

Pot daikon radish 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 daikon radish

Pot on before it is root-bound. Check daikon radish 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 deep, loose, stone-free sandy loam, ph 6.0-7.0 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 daikon radish 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 daikon radish

Daikon Radish wants deep, loose, stone-free sandy loam, ph 6.0-7.0. Because roots drive deep, it needs deeply dug, friable soil free of stones, hard pans, and fresh manure to grow long and straight. Compacted or rocky ground forks and stunts the roots. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting daikon radish — frequently asked questions

How often should you repot daikon radish?

Pot on seedlings as they grow; not a perennial repot for daikon radish. Daikon Radish is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into deep, loose, stone-free sandy loam, ph 6.0-7.0 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 daikon radish need?

When is the best time of year to repot daikon radish?

Can you put daikon radish straight into a much bigger pot?

No. Even a fast-growing daikon radish 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 daikon radish after repotting?

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