How to trim aquarium plants

How to trim aquarium plants

Trimming plants in your aquarium is an important part of creating a healthy and thriving planted tank. With regular trimming we encourage new growth and many plants will produce new shoots, especially ground cover plants such as hair grass. This article aims to provide you with the why, when and how to trim aquarium plants.

Should aquarium plants be trimmed?

Both growth rates of a particular plant and trimming differ considerably. Excessive trimming can disrupt aquarium balance and it is advisable to use smaller and frequent trimmings. By trimming little and often, the aquarium looks presentably throughout. As plants grow, some leaves will die off making way for new leaves. As this happens, we should be trimming away old leaves to prevent an unsightly collection on the substrate and avoiding algae growth.

Additionally, In order to create a specific design, it is important we trim aquarium plants with a sharp pair of scissors to maintain the shape and appearance of the aquatic plants layout otherwise all the hard work we put into the creation of the aquascape will be wasted.

When is the best time to trim aquatic plants?

Theoretically, aquatic plants can be trimmed whenever. As mentioned above, more frequent trimming is advised and this is very true for fast growers like stem plants. To make things more efficient, the best time to trim aquarium plants would be during your regular maintenance routine. Ideally, do your trimming before you do your water change so that all the trimmed leaves and cut stems will float to the surface (not always) making them much easier to remove.

Cuttings from stem plants can be replaced and will grow as normal.

Not all aquarium plants are the same

Aquarium plants grow differently and can require varied approach when it comes to trimming. Aquarium plants with long stems will grow much faster than other plants which means we should trim stem plants more often. On the other end of the spectrum we have slow growing rhizome plants such as Anubias that require much less regular trimming, instead focus is on preventing leaves develop to densely and the removal of dead leaves.
It is strongly advised to research the growth behaviour of your plants to fully understand how best to maintain them where trimming is concerned.

How to correctly trim an aquarium plant.

  • Stem plants - Ludwigia and Rotala are two examples of a stem plant. Both are very fast growers that can easily reach the surface of the aquarium. When they do reach the surface, they begin to blog the light from reaching the lower parts of the aquarium. To prevent this we need to trim very regularly. Depending on light, co2 and fertilisers, this can be as often as every two weeks. To trim, simply make a clean cut at any point on their stem using a pair of scissors. Additionally, you can replant the cutting back into the substrate and it will start growing to create a thick bushy display.

  • Ground cover plants - A group of plants perfect for covering the substrate to create a carpet appearance in the front area of the aquarium. Foreground plants like these require a lot of trimming to encourage a strong root system and new shoots to appear. The best way to trim such plants is to use a very sharp pair of curved plant scissors. Attempts with poor quality scissors can result in the thin needle-like leaves being bent and trapped, which can cause the roots to be pulled out. This regular trimming coupled with high powered lights will produce a thick plant growth.

  • Rhizome plants - Anubias, Bucephelandra and Java fern are popular plants of this type which are easily identified by their root system. Between the thin roots and the stem of the plants, there are thick rootstock (called Rhizome) which cannot be planted beneath substrate. Instead, these plants are attached to objects above the substrate such as wood, rock etc. The dense rootstock acts similar to a creeping vine and will slowly attach itself to the object, allowing aquascapers to decorate their hardscape very well. Trimming of these plants is only needed when the plant becomes very dense. Using a sharp knife or scissors you can cut through the hardy, dense rootstock to remove the section and reattach to another area of hardscape. Occasionally, dead leaves will require pruning with tweezers or scissors. Java fern is great when grown on bog wood.

  • Rosette plants - Cryptocoryne and Amazon swords are two examples of rosette plants. Both plant directly into the substrate and have their roots and stems all coming from a central point. When not comes to trimming, As long as care is taken to avoid damaging the central root area( also known as rhizome), simply trimming away dying or decaying leaves when necessary will be enough to encourage new leaves.

  • Moss - Often we forget about them when we talk about trimming plants but moss can and will require trimming back at some point to prevent it from taking over a specific area. Moss can be easily maintained by regularly trimming back using curved aquascaping scissors. However, a word of warning, turn off your filtration prior to trimming moss. When moss is trimmed, it will float and if the filter is on, the moss will float about into the hardscape which will result in new growth all over the tank.


Aquarium plants should be viewed no different to house plants when it comes to trimming. Trim back the longest shoots, replant the cut stems and don't forget to trim away dying leaves. Keep all this in mind and with an idea of what you wish to achieve, you will reach your goal in no time.
A healthy plant can be easily cut and especially stem plants, can be propagated to rapidly increase the volume of plants in an aquarium.