Repotting guide

When & how to repot Burdock 'Takinogawa' (Arctium lappa 'Takinogawa')

Also called Takinogawa burdock, gobo, greater burdock.

More about burdock 'takinogawa'

About Burdock 'Takinogawa'

Arctium lappa 'Takinogawa' · also called Takinogawa burdock, gobo · edible

'Takinogawa' is the classic Japanese gobo, a burdock selection grown for its long, slender, deeply flavoured taproot. Sown in spring, it drives a root up to a metre into loose soil over a single season. Robust and easy in deep, stone-free ground, it is a staple of kinpira and simmered dishes prized for its earthy, nutty crunch.

Mature size: Leaf rosette reaches 60-100 cm tall and wide; the harvested root grows 60-100 cm long and 2-3 cm thick in a single season.

Watch for — Forked or stunted roots: Stones, compacted soil, or fresh manure split and deform the taproot. Cultivate deeply and remove stones, or grow in a tall loose-filled bed.

How to tell burdock 'takinogawa' needs repotting

Repotting on a calendar is less reliable than reading the plant. For burdock 'takinogawa', 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 burdock 'takinogawa' 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 burdock 'takinogawa'

Pot on seedlings as they grow; not a perennial repot. Burdock 'Takinogawa'is grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Vigorous biennial grown as an annual for its root, forming a large rosette of broad, coarse leaves above a single deep taproot. If left to a second year it bolts to a tall flowering stalk bearing burred seed heads..

What size pot to step burdock 'takinogawa' up to

Pot burdock 'takinogawa' 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 burdock 'takinogawa'

Pot burdock 'takinogawa' 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 burdock 'takinogawa'

Pot on before it is root-bound. Check burdock 'takinogawa' 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 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 burdock 'takinogawa' 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 burdock 'takinogawa'

Burdock 'Takinogawa' wants deep, loose, stone-free sandy loam. The metre-long root needs friable, well-dug soil free of stones and compaction, which cause forking and stunting. Work to spade depth or grow in a deep raised bed. Neutral to slightly acidic pH (6.0-7.5) with moderate fertility. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting burdock 'takinogawa' — frequently asked questions

How often should you repot burdock 'takinogawa'?

Pot on seedlings as they grow; not a perennial repot for burdock 'takinogawa'. Burdock 'Takinogawa' 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 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 burdock 'takinogawa' need?

When is the best time of year to repot burdock 'takinogawa'?

Can you put burdock 'takinogawa' straight into a much bigger pot?

No. Even a fast-growing burdock 'takinogawa' 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 burdock 'takinogawa' after repotting?

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