Repotting guide

When & how to repot Ludwigia glandulosa (Ludwigia glandulosa)

Also called glandular primrose-willow, pearlwort Ludwigia.

More about ludwigia glandulosa

About Ludwigia glandulosa

Ludwigia glandulosa · also called glandular primrose-willow, pearlwort Ludwigia · tropical

Ludwigia glandulosa, often sold as 'Ludwigia Perennis', is a striking aquarium stem plant from the southern USA with wavy lance-shaped leaves that flush deep purple, burgundy and copper under strong light. It is moderately demanding, needing high light, CO2 and rich dosing to show its best colour and avoid leggy, green growth.

Mature size: Submersed stems reach 25-50 cm tall with leaves 3-7 cm long; emersed form is greener and lower-growing.

How to tell ludwigia glandulosa needs repotting

Repotting on a calendar is less reliable than reading the plant. For ludwigia glandulosa, 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 ludwigia glandulosa 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 ludwigia glandulosa

Every 12–18 months — sooner if roots show fast. Ludwigia glandulosa's growth habit — upright stem plant with crinkled, wavy-margined lanceolate leaves; branches from the base into a bushy column. — sets the pace. Ludwigia glandulosa, often sold as 'Ludwigia Perennis', is a striking aquarium stem plant from the southern USA with wavy lance-shaped leaves that flush deep purple, burgundy and copper under strong light. It is moderately demanding, needing high light, CO2 and rich dosing to show its best colour and avoid leggy, green growth.

What size pot to step ludwigia glandulosa up to

Step up one pot size — about 2–3 cm (an inch) wider. Ludwigia glandulosa 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 ludwigia glandulosa

Early spring, just as new growth restarts, is the ideal window for ludwigia glandulosa. 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 ludwigia glandulosa

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

Ludwigia glandulosa wants nutrient-rich aquatic substrate. Plant in aquasoil and supplement with root tabs, as it is a heavy root feeder. Emersed, use constantly wet, fertile peaty substrate. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting ludwigia glandulosa — frequently asked questions

How often should you repot ludwigia glandulosa?

Every 12–18 months — sooner if roots show fast for ludwigia glandulosa. Repot ludwigia glandulosa 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 aquatic substrate. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does ludwigia glandulosa need?

When is the best time of year to repot ludwigia glandulosa?

Can you put ludwigia glandulosa straight into a much bigger pot?

No. Even a fast-growing ludwigia glandulosa 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 ludwigia glandulosa after repotting?

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