Propagating Rotala sp. 'Mini Type 2' by Cuttings and Topping

How to propagate the compact Rotala sp. 'Mini Type 2' by cuttings and topping, doubling stems for dense growth under high light and CO2, with trimming tips.

Overview

Rotala sp. 'Mini Type 2' is a very compact cultivar in the Rotala rotundifolia group, family Lythraceae. The parent species is native to Asia — India, China, Taiwan, Thailand, Laos and Vietnam — and has long been a staple of the planted aquarium. As a fast-growing stem plant it is undemanding but light-hungry: under intense illumination the foliage develops wine-red colour, and the compact 'Mini Type 2' shows pink-red tips that make it a favourite for nano scapes and detail plantings.

Propagation Method

Rotala is propagated by cuttings. Cut a few inches off the top of a stem and replant it; new shoots then sprout from the nodes on the remaining rooted stem. You can cut the tops and let the rooted parts regrow, cut and replant the tops, or do both at once to multiply stems quickly. A key trick for density: cut the very tip off each cutting before replanting so the stem branches into two, effectively doubling your stem count.

Step-by-Step

Select a healthy stem and cut a few inches off the top.
Snip the very tip off the cutting so it will branch into two new shoots.
Strip the lowest whorls of leaves so a clean section can be planted.
Plant cuttings about an inch apart at first so each gets enough light and avoids overcrowding.
Leave the rooted lower portions in place; fresh shoots will sprout from their nodes.
Once the cuttings fill in, pack them more densely to build a tight, bushy stand.

Conditions for Healthy Growth

With sufficient light and CO2 the plant grows with much better density and coloration; the cultivar needs that high light and CO2 to keep its compact, colorful form. It requires medium to very high light, and loss of the lower leaves is a clear sign of insufficient lighting. Although the species is tolerant of a wide range of water parameters and can acclimate to tanks without CO2 injection, the compact red-tipped look depends on strong light and CO2 over soft, acidic water and a rich substrate.

Trimming and Maintenance

This Rotala responds beautifully to topping. You can trim the plant and a week later have very dense, bush-like growth without even replanting the cuttings, because each cut stem pushes multiple new branches. Regular topping every couple of weeks keeps the stand low, compact and richly coloured, and the trimmed tops become free new stock.

Common Challenges

Bare lower stems and dropped leaves signal too little light; increase intensity for the demanding compact form.
Pale green growth with no pink-red tips means light and CO2 are too low for full coloration.
Overcrowded cuttings shade each other early on; space them about an inch apart until they establish.