Propagating Ludwigia sp. 'Atlantis' from Cuttings

How to multiply the deep-red hybrid Ludwigia 'Atlantis' by cutting the tops and replanting them, with the light and nutrient levels that drive branching and colour.

Overview

Ludwigia sp. 'Atlantis' is a cultivated red-toned form within the genus Ludwigia, part of the family Onagraceae. The genus comprises about 82 species of aquatic plants with a cosmopolitan but mainly tropical distribution, known by common names such as water-primrose and primrose-willow. As a stem plant it can be grown submerged and emersed, and 'Atlantis' is prized for intense red to orange-red colour that shows even under moderate light.

That tolerance makes it a useful bridge between easy and demanding red stems, but it still rewards good light and feeding. Because it is a cultivar rather than a wild species, it is multiplied vegetatively to keep its colour true.

Propagation Method (Cuttings)

Ludwigia branches willingly and is easily propagated through the cut-offs. You cut the stem at a node some distance below your target height, replant the top, and the remaining lower part sprouts side shoots to fill in the area. The result is more stems from each plant you trim.

Step-by-Step

1. Cut a healthy stem at a node, taking a top section of about 5-10 cm.
2. Strip the lowest leaves so a clean node can be buried in the substrate.
3. Replant the cutting into nutrient-rich substrate to root the bare node.
4. Leave the base in place; side shoots will sprout from the lower part to fill the gap.
5. Keep light and nutrients up so the cutting roots and holds its red tone.

Conditions for Healthy Growth

Red Ludwigia needs higher light for good colour — roughly 70-80 µmol PAR is enough, and at that level and above the plant both colours up and produces more side shoots. Higher nutrient levels likewise drive more branching, so balanced fertilisation pays off. Although 'Atlantis' colours under moderate light, stronger light, CO2 and a well-balanced fertilisation routine give the deepest reds.

Trimming & Maintenance

Top the plant at a node below the height you want and replant the cut tops; the base branches to thicken the group. Regular trimming keeps the stand dense and lets you steadily expand the planting from your own cuttings rather than buying more stems.

Common Challenges

• Weak or fading colour — light is below the ~70-80 µmol PAR the plant wants.
• Sparse, unbranched stems — too little light or too few nutrients for side shoots.
• Slow rooting of cuttings — bury a clean node and keep light and ferts steady.