Monte Carlo

Overview

Monte Carlo (Micranthemum tweediei) is a carpeting plant with tiny round, bright green leaves that forms thick, cushiony mats. It comes from Argentina, where it grows along stream banks, and was introduced to the hobby by Tropica in 2010. It quickly became the go-to alternative to the notoriously fussy Hemianthus callitrichoides 'Cuba'.

Hobbyists love it because it is more forgiving, grows a little faster and has slightly larger leaves, so it is easier to handle and replant. It is perfect for the foreground of aquascapes and for anyone wanting a real carpet without an extreme setup.

Care and tank setup

With medium light and CO2, Monte Carlo covers the ground in a few weeks. Without CO2 it can still carpet, but more slowly and less tightly.

• Light: medium to high. In low light the stems lift up and it loses its creeping habit.
• CO2: recommended. In low-tech tanks, keep lighting moderate and fertilize well to avoid algae.
• Substrate: fine-grain aqua soil; in coarse gravel it struggles to root and floats away.
• Planting: split the pot or tissue-culture cup into fingernail-sized portions and plant them about 1 inch apart.
• Placement: foreground, in front of rocks or driftwood, under direct light.

Common mistakes: planting large chunks that uproot and float, and neglecting flow. A very dense carpet traps debris and can rot underneath. Digging fish may pull it up while it is establishing.

Fertilizing and trimming

It needs a complete liquid fertilizer, plus root tabs if the substrate is inert. Yellow or see-through leaves usually point to iron or nitrogen deficiency. When the carpet gets thick, trim it close with curved scissors and siphon the clippings thoroughly. If it starts lifting in layers, remove a section and replant young portions so the base doesn't rot.

Propagation

It spreads by creeping runners that root at every node and gradually cover the substrate. You can cut rooted pieces and replant them elsewhere or in another tank. It also grows very well emersed, so the dry start method, with damp soil and the tank covered with plastic wrap, is an excellent way to get a closed carpet before flooding.

Recommended equipment

What you need to keep the Monte Carlo healthy, checked against Amazon stock.