Repotting guide

When & how to repot Chinese Artichoke (Stachys affinis)

Also called Chinese artichoke, crosne, Japanese artichoke, artichoke betony.

More about chinese artichoke

About Chinese Artichoke

Stachys affinis · also called Chinese artichoke, crosne · edible

Chinese artichoke (Stachys affinis), also called crosne, is a hardy perennial in the mint family grown for small, knobbly, pearl-white tubers with a crisp, nutty, water-chestnut-like flavour. The plants form spreading clumps of mint-like foliage above networks of edible rhizomes. Tubers are lifted in autumn and winter, eaten raw, pickled or lightly cooked, and the plant can become invasive from missed tubers.

Mature size: 30-45 cm tall, spreading 30-60 cm wide; tubers 3-8 cm long.

Watch for — Invasive spread: Tubers left in the ground at harvest resprout and the clump wanders. Lift thoroughly each year or contain it in a bed or large pot.

How to tell chinese artichoke needs repotting

Repotting on a calendar is less reliable than reading the plant. For chinese artichoke, 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 chinese artichoke 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 chinese artichoke

Pot on seedlings as they grow; not a perennial repot. Chinese Artichokeis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Spreading, clump-forming herbaceous perennial with square stems and crinkled mint-like leaves; produces dense underground stolons tipped with segmented white tubers..

What size pot to step chinese artichoke up to

Pot chinese artichoke 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 chinese artichoke

Pot chinese artichoke 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 chinese artichoke

Pot on before it is root-bound. Check chinese artichoke 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 light, fertile, free-draining loam, ph 6.0-7.5 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 chinese artichoke 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 chinese artichoke

Chinese Artichoke wants light, fertile, free-draining loam, ph 6.0-7.5. Loose, friable soil enriched with compost lets tubers form and makes them easier to lift cleanly. Heavy, compacted ground gives small, hard-to-clean tubers. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting chinese artichoke — frequently asked questions

How often should you repot chinese artichoke?

Pot on seedlings as they grow; not a perennial repot for chinese artichoke. Chinese Artichoke is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into light, fertile, free-draining loam, ph 6.0-7.5 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 chinese artichoke need?

When is the best time of year to repot chinese artichoke?

Can you put chinese artichoke straight into a much bigger pot?

No. Even a fast-growing chinese artichoke 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 chinese artichoke after repotting?

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