Repotting guide

When & how to repot Rotala macrandra (Rotala macrandra)

Also called giant red Rotala, broadleaf Rotala.

More about rotala macrandra

About Rotala macrandra

Rotala macrandra · also called giant red Rotala, broadleaf Rotala · tropical

A striking high-tech aquascaping stem plant with broad, ruffled leaves that turn deep pink to fiery red. More demanding than common rotalas, it needs strong light, stable CO2 and lean dosing to avoid stunting. A showpiece background or midground plant for experienced aquarists who can hold consistent water parameters.

Mature size: Stems reach 20-40 cm tall with leaves up to 3-4 cm long; branches into a wide, leafy clump.

How to tell rotala macrandra needs repotting

Repotting on a calendar is less reliable than reading the plant. For rotala macrandra, 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 macrandra 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 macrandra

Every 12–18 months — sooner if roots show fast. Rotala macrandra's growth habit — upright branching stem plant with broad opposite leaves, forming a bold red bush; moderate growth rate that slows and stunts if parameters shift. — sets the pace. A striking high-tech aquascaping stem plant with broad, ruffled leaves that turn deep pink to fiery red. More demanding than common rotalas, it needs strong light, stable CO2 and lean dosing to avoid stunting. A showpiece background or midground plant for experienced aquarists who can hold consistent water parameters.

What size pot to step rotala macrandra up to

Step up one pot size — about 2–3 cm (an inch) wider. Rotala macrandra 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 macrandra

Early spring, just as new growth restarts, is the ideal window for rotala macrandra. 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 macrandra

Time it for spring. Repot rotala macrandra 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 macrandra out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh nutrient-rich 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 macrandra 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 macrandra

Rotala macrandra wants nutrient-rich aquasoil substrate. Best rooted in active aquasoil with root tabs. A fertile substrate plus lean water-column dosing supports the strong, well-coloured growth this species demands. 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 macrandra — frequently asked questions

How often should you repot rotala macrandra?

Every 12–18 months — sooner if roots show fast for rotala macrandra. Repot rotala macrandra 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 nutrient-rich aquasoil substrate. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does rotala macrandra need?

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

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

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

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