Propagating Rotala mexicana 'Goias'

How to propagate the fine-leaved Rotala mexicana 'Goias' from stem cuttings: topping technique, replanting, and the high light plus CO2 conditions that bring out its color.

Overview

Rotala mexicana 'Goias' is a fine, needle-leaved aquascaping form of the genus Rotala, which belongs to the loosestrife family (Lythraceae). Several Rotala species are widely used as aquarium plants, grown as fast, upright stem plants that form dense bushes in the midground.

Like other Rotala, it is an amphibious plant: it can grow both submerged and emersed in shallow water. Submerged growth tends to be narrow and delicate, and under intense illumination the foliage develops warm reddish to orange tones, which is why this form is prized in competition aquascapes.

Propagation Method

Rotala is propagated by stem cuttings. Because each cutting readily roots and continues to grow, taking and replanting tops is the standard way to multiply the plant and to keep a bush dense. This is the same cutting-based method documented across the genus.

Step-by-Step

Select healthy, vigorously growing stems with good color.
Using clean, sharp scissors, cut the top 5-8 cm of a stem just above a node.
Strip the leaves from the lowest 1-2 cm of the cutting so a clean section can be buried.
Plant the cutting into nutrient-rich substrate, spacing several cuttings close together to build a full bush.
Leave the trimmed parent stem in place; it will branch and send up new shoots from below the cut.

Conditions for Healthy Growth

This is an intermediate, demanding form. It thrives in warm water (about 22-28 C), soft to moderately hard water, and a slightly acidic to neutral pH. High light and supplemental CO2 are key: insufficient light causes lower-leaf loss in Rotala, while strong illumination drives the compact growth and red-orange coloration.

Trimming & Maintenance

Trim roughly every two weeks. Topping the bush both controls height and produces fresh cuttings to replant. Frequent, even trimming encourages branching and keeps the stand dense; the trimmed tops are the most vigorous material for propagation.

Common Challenges

Without enough light the lower stems shed leaves and go bare, leaving a thin, leggy bush. Low CO2 or poor nutrients dull the color back toward plain green. Because submerged and emersed forms differ, plants grown emersed will need an adjustment period when first submerged.