Repotting guide

When & how to repot Vietnamese Perilla (Perilla frutescens var. purpurascens)

Also called Vietnamese Perilla, Tia To.

More about vietnamese perilla

About Vietnamese Perilla

Perilla frutescens var. purpurascens · also called Vietnamese Perilla, Tia To · herb

Vietnamese perilla (tia to) is an aromatic annual with distinctive bicoloured leaves, green above and deep purple-red beneath, used fresh in Vietnamese soups, salads, and herb plates. A close relative of shiso, it grows fast in warm, moist, fertile conditions, benefits from afternoon shade where summers are hot, and self-seeds readily once allowed to flower.

Mature size: 45-90 cm tall and 30-45 cm wide.

How to tell vietnamese perilla needs repotting

Repotting on a calendar is less reliable than reading the plant. For vietnamese perilla, 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 vietnamese perilla 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 vietnamese perilla

Pot on seedlings as they grow; not a perennial repot. Vietnamese Perillais grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Upright, branching aromatic annual with square stems and broad, serrated, frilly leaves that are green above and purple-red beneath; sends up slender flower spikes in late summer..

What size pot to step vietnamese perilla up to

Pot vietnamese perilla 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 vietnamese perilla

Pot vietnamese perilla 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 vietnamese perilla

Pot on before it is root-bound. Check vietnamese perilla 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 vietnamese perilla 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 vietnamese perilla

Vietnamese Perilla wants fertile, moisture-retentive loam. Rich, humus-rich, well-drained soil, pH 5.5-6.5. Dig in compost before planting; poor dry soils give small, hard leaves with weaker flavour and colour. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting vietnamese perilla — frequently asked questions

How often should you repot vietnamese perilla?

Pot on seedlings as they grow; not a perennial repot for vietnamese perilla. Vietnamese Perilla 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 vietnamese perilla need?

When is the best time of year to repot vietnamese perilla?

Can you put vietnamese perilla straight into a much bigger pot?

No. Even a fast-growing vietnamese perilla 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 vietnamese perilla after repotting?

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