Propagating Ludwigia ovalis 'Sumatra'

How to propagate the round-leaved Ludwigia ovalis 'Sumatra' from stem cuttings: topping and replanting, plus the light it needs to turn its rounded leaves pink-red.

Overview

Ludwigia ovalis 'Sumatra' is a Sumatran form of Ludwigia ovalis, a stem plant set apart from most Ludwigias by its rounded, oval leaves on creeping stems. Under strong lighting the upper leaves shift from green toward pinkish-red and deep red, giving a distinctive ombre effect. As a cultivar it is propagated only from cuttings, so new plants are clones of the parent and behave the same way.

Propagation Method (Cuttings)

Ludwigia ovalis is propagated by stem cuttings, like the rest of the genus: cut a top section, strip the lower leaves and replant it. When pruned, the base shoots out one or two new stalks that grow toward the surface and then spread horizontally, so a single topping both renews the parent and gives a cutting to plant elsewhere.

Step-by-Step

1. Cut the top 5-10 cm of a healthy stem just above a leaf node.
2. Strip the leaves off the lower portion of the cutting so a bare section can be buried.
3. Plant each stem at least 5-8 cm deep, even if the substrate covers the lowest leaves, so it anchors and roots.
4. Space cuttings close together for a fuller, bushier group.
5. Leave the trimmed base in place: it will push one or two new shoots toward the light.

Conditions for Healthy Growth

Give Ludwigia ovalis 'Sumatra' plenty of light and liquid fertilizer for faster growth and vibrant color. The rounded leaves only blush pink-red in higher light; in lower light they stay green. At least some CO2, around 10 ppm and up, improves coloration and helps the plant branch into a denser bush after repeated pruning. A nutrient-rich substrate suits its fibrous roots, and it accepts a broad range of soft-water parameters.

Trimming & Maintenance

Top the stems regularly and replant the trimmings to multiply the plant. Because color sits on the crown, frequent trimming keeps the planting low, bright and compact. Stem cuttings root within a few days under good conditions, and the creeping habit means it can also be guided to fill a midground patch.

Common Challenges

• Green instead of pink leaves usually means light is too low; raise intensity or thin the group.
• Leggy, sparse stems point to shading from an overgrown stand.
• Slow or sparse growth improves with added CO2 and regular liquid fertilizer.
• Emersed growth produces different leaves; the round submersed form needs steady underwater conditions.