Propagating Ludwigia peruensis ('Peruensis' / 'Diamond')

How to propagate the broad red-stemmed Ludwigia peruensis (the glandulosa/peruensis group) by cuttings and topping, and how strong light, CO2 and iron drive its red-to-orange coloration.

Overview

Ludwigia peruensis belongs to the glandulosa/peruensis group of broad-leaved red ludwigias in the family Onagraceae; the closely associated Ludwigia glandulosa was historically sold as Ludwigia perennis. It is a vertical stem plant reaching roughly 15–40 cm, of medium growth and medium difficulty, whose foliage shifts toward red and orange under good light rather than turning green.

Propagation Method

Like other ludwigias it branches willingly and is propagated by cuttings and topping. When you cut the top off a stem, the cut top is replanted as a new plant while the remaining base sends out side shoots, so each topping multiplies the plant and thickens the group at the same time.

Step-by-Step

Cut the stem at a node some distance below the final height you want the plant to reach, staggering cut heights for a natural slope.
Take a 5–10 cm top cutting and strip the lower leaves so a clean node is exposed.
Push the bare node into nutrient-rich substrate and let it root.
Leave the topped base in place; new side shoots will appear at the cut.
As shoots grow, remove any outlying ones that do not match the slope to keep tidy clusters.

Conditions for Healthy Growth

Coloration is light-driven: around 70–80 umols PAR is enough for good color, and higher light (80 umols+) also pushes more side shoots. At least 10 ppm CO2 improves color and branching, and roughly 30 ppm suits most demanding plants. Well-balanced fertilization with iron supports red pigment, supplied either at the roots or in the water column.

Trimming & Maintenance

Trim roughly every week to ten days. Repeated pruning at the node produces denser bushes as the base branches out, and each removed top becomes a new plant. Stagger cut heights to maintain a sloped, layered background.

Common Challenges

Loss of red: too little light, CO2 or iron causes leaves to green out or yellow and drop.
Leggy stems: insufficient light makes stems stretch with sparse foliage.
Emersed-to-submersed transition: emersed-grown stock may melt initial leaves before settling into red submersed growth.