Propagating Ammannia 'Bonsai'

How to propagate the compact red-stem cultivar Ammannia 'Bonsai' by cuttings, with the light, CO2 and iron levels needed to keep its colour and tight form.

Overview

Ammannia 'Bonsai' is a compact cultivar of the genus Ammannia, a group of over 100 flowering plants in the family Lythraceae. These plants are commonly called redstems and come from wet areas across America, Africa, Asia, Australia and Europe, and several Ammannia species are grown as decorative aquarium plants.

Like its parent group, 'Bonsai' is a stem plant that takes on shades of yellow, orange and red depending on conditions. It stays small with rounded leaves on short internodes, which makes it useful as a foreground or midground accent in nano scapes.

Propagation Method (Cuttings)

As a stem plant, Ammannia 'Bonsai' is propagated by cuttings. You cut the top section of a healthy stem and replant it, and the remaining base sends out side shoots so a single plant slowly multiplies into a cluster. The cultivar is propagated the same way as the parent Ammannia stems.

Step-by-Step

1. Choose a healthy stem with good colour and tight internodes.
2. Cut the top 5 to 10 cm off using clean, sharp scissors.
3. Strip the leaves from the lowest 2 to 3 cm of the cutting.
4. Push the bare base into nutrient-rich substrate, leaving the foliage clear.
5. Leave the trimmed base in place so it branches into new side shoots.
6. Replant the side shoots later to thicken the group.

Conditions for Healthy Growth

Ammannia shows its best red and pink tones under high light and added CO2; under medium light it stays greener and more yellow. To pull out and hold the red, give it strong light, pressurised CO2 and good iron and nutrient availability, with a nutrient-rich substrate underneath.

Trimming & Maintenance

Because 'Bonsai' is slow-growing, it needs trimming only about every two weeks. Each topping doubles as propagation: replant the cut tops and let the bases branch. Keep faster neighbours from shading it so the lower stems stay coloured.

Common Challenges

• Loss of red colour — usually too little light, CO2 or iron.
• Stunted or melting tips — unstable CO2 or poor nutrient supply.
• Leggy stems with long internodes — light too weak for this compact form.
• Slow recovery after cutting — normal for this slow-growing cultivar; be patient.