Limnophila aromatica / hippuridoides is an easy stem plant that originates from Asia. It is often found as a weed in Asia rice paddy fields and is used as an aromatic herb (Ngò om) in some Vietnamese soups. There is some confusion between L. aromatica and hippuridoides and you can read about the differences here. Generally, L. hippuridoides has more leaves (6-8) per node and is more reddish while L. aromatica is more variable (3-8 leaves) and have varietals that are greenish or reddish. They have similar requirements otherwise.
They can be identified by their serrated leaf edges and aromatic scent. They grow tall easily and will reach the water surface of most tanks, and have a diameter of between 2 to 2.5 inches. The emersed forms have less leaves compared to submerged forms.
Limnophila aromatica is tolerant of a wide range of water parameters and are easy plants to grow. The grow tall and aggressively and are best used as background plants. Due to its coarser leaf texture, it seems to be less favored in today's aquascapes. However, we find that it forms attractive clusters with good coloration.
Limnophila aromatica is a good background filler with attractive foliage. Here, it contrasts sharply with Ludwigia sp. red and Myriophyllum 'Guyana'.
They can be trimmed aggressively. This encourages side shoots to form and the plant can become very bushy. It is very resilient to being grown densely, and can be pruned for many months without requiring replanting (the bottoms portions don't deteriorate so easily and will sprout new shoots when the plant is trimmed down). It can tolerate a certain amount of self shading without issue.
Low nitrates causes the topside of the leaves to become significantly redder
Get the varietal that is redder
This is one of the plants that exhibit redder colors under nitrate limitation. Over-do this however, and the plant will stunt.
Under low nitrates, the topside of the leaves can turn significantly redder.
How to trim
Cut off the stem at a node some distance below the final height that you want the plant to grow to. Stagger the cutting height shorter at the front and taller at the back to get a nice slope. As new shoots appear on the cut stem base, cut off outlier shoots that do not match the slope of the cluster. Over time, this will produce neat bunches of plants.