Rotala rotundifolia

Overview

Rotala rotundifolia is one of the most popular stem plants, valued for fast, bushy growth and tips that flush pink, orange and red under strong light. Planted in groups it forms a soft, colourful bush in the midground or background. It is a stem plant, which means it is propagated and shaped by trimming and replanting — and being fast-growing, it is also excellent at soaking up excess nutrients and starving out algae.

Planting & placement

Plant Rotala stems individually into the substrate, spaced a centimetre or so apart so each has room and light — a group of stems reads as one full bush. It suits the midground and background, where its height and colour draw the eye. Remove any lower leaves that would be buried before pushing the stem in. See how to plant aquarium plants for stem-planting technique and aquascaping for beginners for grouping.

Light, CO2 & ferts

Rotala grows in medium light, but high light plus CO2 unlocks its compact, colourful best — the tops turn red and the growth stays dense rather than stretched. Feed a complete liquid fertilizer; as a fast grower it is hungry, and iron in particular supports red tones. Our best light for a planted tank guide covers intensity for good colour.

Propagation & problems

Propagate by trimming and replanting: snip the top few centimetres of a healthy stem and plant the cutting; it roots quickly, and the cut stem branches into a bushier plant. Regular trimming keeps the group dense and tidy. The main problems are stretched, leggy growth and pale colour (add light and CO2) and lower stems thinning as the canopy shades them (trim and replant tops, thin the group). Pair it with red Ludwigia repens for contrast. Because it grows fast and drinks up nutrients, a healthy stand of Rotala also helps keep algae in check in a well-lit tank. Plant a generous group from the start rather than a few thin stems — the bushy, colourful effect really depends on density, and trimming quickly multiplies your stock.