Monte Carlo
Micranthemum tweediei
intermediate careOverview
Monte Carlo (Micranthemum tweediei) is one of the most popular carpeting plants, forming a lush, bright-green lawn of small round leaves across the foreground. It is a little more forgiving than dwarf hairgrass or dwarf baby tears, but make no mistake — like all carpeting plants it needs high light and CO2 to stay low and dense. Give it those and it delivers one of the most rewarding looks in aquascaping.
Planting & placement
Split the mat into small portions and plant each into a nutrient substrate a couple of centimetres apart across the foreground. More starting portions mean faster coverage. Many aquascapers use the dry-start method — growing Monte Carlo emersed on damp soil under a lid for a few weeks before flooding the tank — to establish a dense carpet before algae can compete. Our how to plant aquarium plants and best substrate for a planted tank guides help here.
Light, CO2 & ferts
This is a high-tech carpet. Strong light reaching the substrate is essential — weak light makes it grow tall and leggy instead of creeping. CO2 is strongly recommended for a flat, compact lawn, and a full liquid fertilizer regime keeps it fed as it grows fast. See our best light for a planted tank and CO2 for beginners guides before committing.
Propagation & problems
Monte Carlo propagates by spreading runners and by division — lift a section, split it, and replant to expand the carpet or fill gaps. Trim the top regularly to force dense, horizontal growth and to stop lower layers from browning and detaching (which can cause the carpet to float up in patches). The main problems — leggy growth and algae — both trace back to too little light or CO2. Compare it with the finer dwarf hairgrass for a grassier carpet, or the much easier, no-CO2 dwarf sagittaria if high-tech gear isn’t for you. Keep the carpet thin by trimming regularly so light reaches the base, and vacuum trapped detritus gently during maintenance. Get the balance right and Monte Carlo delivers a bright, dense lawn that anchors the whole aquascape.
Monte Carlo — frequently asked questions
Can Monte Carlo carpet without CO2?
It can survive without CO2 under strong light, but it grows slowly, patchily and tends to reach upward for light rather than hugging the substrate. For a dense, flat, low carpet, high light plus CO2 is strongly recommended.
Why is my Monte Carlo growing tall instead of carpeting?
Reaching upward means it is not getting enough light at the substrate. Increase light intensity, add CO2, and trim it back — trimming forces horizontal, creeping growth. Insufficient light is the number one reason carpets fail to stay low.
How do I plant a Monte Carlo carpet?
Split the mat into small portions and plant each into a nutrient substrate a couple of centimetres apart. Many aquascapers use the dry-start method — growing it emersed on damp soil before flooding — for the fastest, most even carpet.
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