Propagating Rotala macrandra 'Narrow Leaf' from Cuttings

A practical guide to propagating the narrow-leaved red macrandra by stem cuttings, with the soft water, intense light, CO2 and iron this demanding cultivar needs to stay red.

Overview

Rotala macrandra 'Narrow Leaf' (also called 'Mini') is a narrow-leaved selection of Rotala macrandra, a stem plant of the loosestrife family (Lythraceae) from Asia, with India given as the origin of this form. Compared with the broad type it has finer foliage and reaches intense red under strong light and CO2. It is propagated vegetatively from cuttings, so propagated stems keep the narrow-leaf habit of the parent.

Propagation Method (Cuttings)

Narrow Leaf comes only from vegetative propagation. As with all macrandra, cut the longest stems 5-10 cm from the substrate and replant them in groups; the base then pushes new side shoots while the replanted tops grow on. Topping the same stand repeatedly works, but tissue tires over several cycles, so periodic replanting of fresh tops keeps the group vigorous.

Step-by-Step

Pick a healthy stem 12-15 cm or taller with strong red, narrow upper leaves.
Cut the top 5-10 cm with clean, sharp scissors.
Strip the leaves from the lowest 2-3 cm to expose a clean node.
Plant the cutting into nutrient-rich substrate, burying the stripped node, and group several together.
Leave the base in place to throw side shoots for the next harvest.

Conditions for Healthy Growth

Grow this cultivar in soft, acidic, low-alkalinity water. It needs high-quality lighting; roughly 150 umol PAR at the substrate is very-high light that drives the density and deep colour red macrandra is grown for. CO2 injection (about 15-25 mg/L) is vital, and consistency matters more than peak concentration — CO2 dips readily cause tip stunting in the narrow-leaf form.

Trimming & Maintenance

Trim roughly weekly to keep the stand dense and the red tops in the light. After several trim cycles the planting tires, so cut and replant the adapted top portions and discard the old uprooted base. Macrandra is amphibious; the emersed form looks different from the submersed one, and emersed-grown stock reshapes its leaves as it adapts underwater.