Propagating Ludwigia repens 'Rubin' from Cuttings

How to propagate the wine-red cultivar Ludwigia repens 'Rubin' by stem cuttings, with the light, iron and CO2 conditions that keep its broad leaves deeply coloured.

Overview

Ludwigia repens 'Rubin' is a deep wine-red, broad-leaved cultivar of Ludwigia repens, a species in the evening primrose family (Onagraceae). The parent is a mat-forming perennial herb with a creeping stem reaching up to 30 cm that roots at the nodes where they touch wet substrate. As a selected colour form, 'Rubin' is propagated in exactly the same way as the parent species, and every cutting carries the cultivar's red pigmentation forward.

Propagation Method (Cuttings)

Like other Ludwigia, 'Rubin' branches willingly and is propagated entirely by stem cuttings. Topping the plant removes the growing tip, while the cut base reliably pushes out side shoots, so a single stem multiplies into a fuller bush with each pruning. Because the species roots at its nodes, a detached top forms its own roots once planted.

Step-by-Step

1. Choose a healthy, well-coloured stem and cut the top 5-10 cm, ideally a node below the height you want.
2. Strip the leaves from the lowest 2-3 cm so they will not rot in the substrate.
3. Plant the cutting into nutrient-rich substrate, spacing stems so light reaches each one.
4. Leave the rooted base in place; it will branch into new side shoots.
5. Stagger cutting heights, shorter at the front and taller at the back, for a natural slope.

Conditions for Healthy Growth

Colour in Ludwigia tracks light: it grows at lower light (around 40 umol PAR) but higher light (80 umol PAR and up) deepens the red and triggers more side shoots. At least some CO2 (10 ppm or more) improves colouration and branching, producing denser bushes after repeated pruning, though the plant still grows without injected CO2. Iron supplementation and a nutrient-rich substrate further support the ruby tone.

Trimming & Maintenance

Trim every week or so to keep the group dense; each top you remove becomes a new plant and each cut base branches again. Note that emersed and submersed growth differ in leaf size and rigidity in Ludwigia, so freshly submersed tops may adjust their form before settling into their underwater leaves.

Common Challenges

Weak or green-tinged growth almost always means too little light, iron or CO2 rather than a propagation fault. Crowded, shaded lower stems drop their leaves, so thin the group and replant healthy tops. As an aquatic species with weedy potential, never release trimmings into natural waterways.