How to grow Myriophyllum 'Guyana'

Introduction

Myriophyllum 'Guyana' is a recent addition to the aquarium hobby. Myriophyllum 'Guyana' is a green stem plant with a maximum diameter of about one inch. Whilst many Myriophyllum species have been in the hobby for a long time, this species stands out for its much smaller form. This allows it to be easily shaped into dense, attractive bushes even in smaller tanks. It can provide a great contrast to other non-green plants. It is a great filler plant, producing side shoots to fill the surrounding space.

Higher light levels (90PAR+) and CO2 injection will give denser forms as this will allow the plant to branch more profusely.

Myriophyllum 'Guyana' is a little more delicate than other super hardy larger sized Myriophyllum species. Planting it in a mature aquarium will reduce acclimatisation stress. The plant tends to get algae more easily than more robust Myriophyllum species and does better in tanks that are well maintained and clean.

Although it tolerates pruning well, the lower parts of the plant will still deteriorate after repeated pruning and eventually we will need to uproot and discard the deteriorating old bottoms and replant fresh tops. This topping-off and replanting cycle needs to be repeated every few months to keep the bush fresh.

Myriophyllum 'Guyana' tolerates hard water.

Key success factors:

• Higher PAR levels (90 umols+)  allow for denser, more branching growth.

• CO2 injection highly recommended - this species does not do as well as other Myriophyllum species without CO2 injection. The TC transition is much better with CO2 injection, while mature plants are more robust.

• Plant in a mature, cycled tank. This plant can be vulnerable to algae as its leaves are delicate. 

• Regular fertilization maintains bright, fresh green leaves.

• Regular, strategic pruning to keep it in good form. Easily reaches the top of most tanks given enough time.

Trimming & propagation

Myriophyllum 'Guyana' is a fast-growing stem plant, so propagation is easy; cut off the top 3 to 4 inches of the stem and replant, leaving the bottom part to sprout new shoots. After many cycles of pruning, the lower parts of the plant will deteriorate and this can be seen as the lower stems become bare. Older, deteriorating growth is susceptible to algae and takes longer to recover. This can result in a less dense or uneven shrub.

The shrub can and should be refreshed periodically by uprooting and discarding the old growth, followed by clearing the aquasoil area of excess detritus, then cutting and replanting fresh new tops (3-4 inches) of plants. This technique can be used to refresh most stem plant bushes which, after some time, are faced with deteriorating soils.