Propagating Bacopa salzmannii 'Purple' from Cuttings

How to multiply purple bacopa, a compact South American stem plant, using head and partial cuttings while keeping its purple coloration.

Overview

Bacopa salzmannii 'Purple' is a South American stem plant with a medium growth rate that reaches about 30 cm. It is roughly half the size of Bacopa caroliniana and carries vibrant purple and green tones that intensify under medium to high lighting. It suits the midground or background, where it adds depth and colour contrast.

The plant is rated easy and is propagated entirely from stem cuttings, making it a reliable choice for aquascapers who want a colourful purple stem without difficult care.

Propagation Method (Cuttings)

Bacopa salzmannii is multiplied by head cuttings and partial cuttings. After a stem is cut, it produces plenty of side shoots from the remaining base, so a single trimmed plant quickly becomes several.

Step-by-Step

Cut the top 5-10 cm of a healthy stem with clean scissors, just above a leaf node.
Strip the lowest pair of leaves so the bare nodes can be buried.
Plant the cutting a few centimetres into the substrate in the midground or background.
Leave the trimmed parent in place; its base will send out new side shoots.
Space several cuttings a short distance apart to form a dense group.

Conditions for Healthy Growth

Bacopa salzmannii needs medium to strong lighting and a complete macro- and micronutrient supply through the water column; a nutrient-rich substrate and CO2 addition are advantageous. Higher PAR (around 100 umol and above) brings out the strongest purple, and even the greener forms turn purple under high light.

Compared with the hardiness-tolerant Bacopa caroliniana, B. salzmannii prefers softer water. CO2 in the medium range (about 6-14 mg/L) and regular fertilization maximise both growth and colour.

Trimming & Maintenance

Because cutting triggers side shoots, regular topping both controls height and thickens the stand. Replant the removed tops to expand the group, and keep light and nutrients steady so new growth holds its purple tone.

Common Challenges

Pale or fully green growth almost always means too little light — raise PAR or move the plant higher in the tank. Brighter lighting can also encourage algae on Bacopa, so balance light with nutrients and CO2 rather than overdriving intensity alone.