Repotting guide

When & how to repot Thai Aubergine (Solanum melongena 'Thai Green')

Also called Thai green eggplant, Thai aubergine, pea eggplant.

More about thai aubergine

About Thai Aubergine

Solanum melongena 'Thai Green' · also called Thai green eggplant, Thai aubergine · edible

'Thai Green' is a small, round, golf-ball-sized green-and-white aubergine used in Southeast Asian curries, with firm, slightly bitter flesh eaten when immature. Heat-loving and very productive, the bushy plants set many small fruit and crop best under glass or in a long, hot summer outdoors in cool-temperate regions.

Mature size: 75-120 cm tall and 45-60 cm wide; round fruit 4-6 cm across

Watch for — Won't fruit without enough heat: This is the most heat-demanding of common aubergines; cool summers give leaf but few fruit. Grow under glass or in the hottest spot and start plants early indoors.

How to tell thai aubergine needs repotting

Repotting on a calendar is less reliable than reading the plant. For thai aubergine, 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 thai aubergine 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 thai aubergine

Pot on seedlings as they grow; not a perennial repot. Thai Aubergineis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Bushy, branching tender perennial grown as an annual, often slightly taller and more open than large-fruited types. Sets many small fruit in clusters; light staking helps, and regular picking keeps new fruit coming..

What size pot to step thai aubergine up to

Pot thai aubergine 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 thai aubergine

Pot thai aubergine 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 thai aubergine

Pot on before it is root-bound. Check thai aubergine 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, free-draining loam or potting mix rich in organic matter, ph 5.5-6.8 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 thai aubergine 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 thai aubergine

Thai Aubergine wants fertile, free-draining loam or potting mix rich in organic matter, ph 5.5-6.8. Wants warm, fertile, well-drained soil. Containers and grow bags suit cool climates as they warm fast. Avoid cold, sodden, heavy ground, which stalls these heat-demanding plants. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting thai aubergine — frequently asked questions

How often should you repot thai aubergine?

Pot on seedlings as they grow; not a perennial repot for thai aubergine. Thai Aubergine is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into fertile, free-draining loam or potting mix rich in organic matter, ph 5.5-6.8 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 thai aubergine need?

When is the best time of year to repot thai aubergine?

Can you put thai aubergine straight into a much bigger pot?

No. Even a fast-growing thai aubergine 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 thai aubergine after repotting?

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