Repotting guide

When & how to repot Spilanthes (Acmella oleracea)

Also called Toothache Plant, Buzz Buttons, Paracress.

More about spilanthes

About Spilanthes

Acmella oleracea · also called Toothache Plant, Buzz Buttons · herb

Spilanthes, the toothache plant, is a low, spreading tender annual grown for its gold-and-red 'eyeball' flower buds and tingling, numbing leaves. Chewing a bud produces a buzzing, saliva-inducing sensation from spilanthol, used traditionally for oral pain. It loves heat, sun, and moist fertile soil, sprawling into a dense edible groundcover and flowering nonstop until frost.

Mature size: 25-35 cm tall and 30-45 cm wide, spreading.

How to tell spilanthes needs repotting

Repotting on a calendar is less reliable than reading the plant. For spilanthes, watch for these signs:

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

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 spilanthes

Every 2–3 years, into bone-dry mix. Spilanthes's growth habit — low, mounding to sprawling tender annual with succulent stems, bronze-tinged ovate leaves, and distinctive cone-shaped gold flowerheads with a central red 'eye'; flowers continuously until frost. — sets the pace. Spilanthes, the toothache plant, is a low, spreading tender annual grown for its gold-and-red 'eyeball' flower buds and tingling, numbing leaves. Chewing a bud produces a buzzing, saliva-inducing sensation from spilanthol, used traditionally for oral pain. It loves heat, sun, and moist fertile soil, sprawling into a dense edible groundcover and flowering nonstop until frost.

What size pot to step spilanthes up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Spilanthes stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

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 spilanthes

Spring or summer, while spilanthes is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting spilanthes

Repot dry. Do not water spilanthes for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty fertile, moisture-retentive loam ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set spilanthes at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep spilanthes completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for spilanthes

Spilanthes wants fertile, moisture-retentive loam. Rich, humus-rich, well-drained soil, pH 6.0-7.0. Incorporate compost before planting; thin or poor soils reduce vigour and flowering. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting spilanthes — frequently asked questions

How often should you repot spilanthes?

Every 2–3 years, into bone-dry mix for spilanthes. Repot spilanthes every 2–3 years into a snug pot of fertile, moisture-retentive loam, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does spilanthes need?

When is the best time of year to repot spilanthes?

Should you water spilanthes after repotting?

No — not straight away. Repot spilanthes into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise spilanthes after repotting?

Not immediately. Wait about 3 weeks after repotting spilanthes. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.