Repotting guide

When & how to repot Rotala rotundifolia (Rotala rotundifolia)

Also called roundleaf toothcup, pink Rotala.

More about rotala rotundifolia

About Rotala rotundifolia

Rotala rotundifolia · also called roundleaf toothcup, pink Rotala · tropical

One of the most popular and forgiving aquascaping stem plants. Submerged, it produces fine needle-like leaves that flush pink, orange or red under strong light, despite the 'roundleaf' name referring to its emersed form. Fast-growing and undemanding, it suits beginners as a lush background plant and tolerates a wide range of tank conditions.

Mature size: Stems grow 25-50 cm tall and will trail along the surface; a single stem branches into a wide clump within weeks.

How to tell rotala rotundifolia needs repotting

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

Roots poking out of the drainage holes or coiling visibly around the inside of the pot.
You are watering far more often than you used to because the rootball dries out within a day or two.
Water runs straight through and out the bottom without soaking in.
Top growth has slowed or new rotala rotundifolia leaves are noticeably smaller than older ones despite good light.

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 rotala rotundifolia

Every 12–18 months — sooner if roots show fast. Rotala rotundifolia's growth habit — vigorous upright stem plant that branches freely and forms dense bushy thickets; readily creeps and sends new shoots, making it ideal for a full background curtain. — sets the pace. One of the most popular and forgiving aquascaping stem plants. Submerged, it produces fine needle-like leaves that flush pink, orange or red under strong light, despite the 'roundleaf' name referring to its emersed form. Fast-growing and undemanding, it suits beginners as a lush background plant and tolerates a wide range of tank conditions.

What size pot to step rotala rotundifolia up to

Step up one pot size — about 2–3 cm (an inch) wider. Rotala rotundifolia grows fast, so it will fill that space within a season, but jumping several sizes at once still backfires: the unused soil stays soggy and rots even a vigorous root system. One size at a time, every year or so, is the rhythm.

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 rotala rotundifolia

Early spring, just as new growth restarts, is the ideal window for rotala rotundifolia. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting rotala rotundifolia

Time it for spring. Repot rotala rotundifolia in early spring as growth restarts so it re-roots quickly into the fresh soil.
Choose one size up. Pick a pot about 2–3 cm wider with drainage holes. One step only — a much bigger pot stays soggy and rots roots.
Ease the plant out. Water lightly the day before, then tip rotala rotundifolia out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh aquarium gravel or aquasoil substrate in the new pot, set the plant so its soil line is unchanged, and backfill, firming lightly.
Water and pause feeding. Water once to settle the soil. Hold off fertiliser for about a month — fresh mix already has nutrients and feeding now burns new roots.

Aftercare

Water rotala rotundifolia once to settle the soil, then let the surface dry before watering again — fresh mix around the roots stays wetter than the old compacted ball, so the commonest post-repot mistake is overwatering. Keep it out of direct sun for a week or two while roots re-establish. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for rotala rotundifolia

Rotala rotundifolia wants aquarium gravel or aquasoil substrate. Roots readily in fine gravel, sand or nutrient aquasoil. It feeds heavily from the water column, so a fertile substrate is helpful but not essential. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting rotala rotundifolia — frequently asked questions

How often should you repot rotala rotundifolia?

Every 12–18 months — sooner if roots show fast for rotala rotundifolia. Repot rotala rotundifolia roughly every 12–18 months, in early spring as growth restarts. It grows fast and circles its pot quickly, so step up one size (about 2–3 cm wider) into fresh aquarium gravel or aquasoil substrate. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does rotala rotundifolia need?

When is the best time of year to repot rotala rotundifolia?

Can you put rotala rotundifolia straight into a much bigger pot?

No. Even a fast-growing rotala rotundifolia 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 rotala rotundifolia after repotting?

Not immediately. Wait about 4 weeks after repotting rotala rotundifolia. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.