The African Water Fern (Bolbitis heudelotii) is a resilient aquatic plant popular for freshwater aquariums and paludariums. Its elegant, dark green foliage provides a natural, jungle-like aesthetic, making it a popular choice for aquascaping enthusiasts. This article guides you on cultivating and maintaining this unique fern species in a home aquatic environment.
Understanding the African Water Fern
This aquatic fern is native to West Africa, naturally growing in fast-flowing rivers, streams, and waterfalls across West Africa. It is characterized by dark green, semi-translucent, and often lobed leaves that can reach up to 18 inches in length. The plant grows from a thick, creeping horizontal stem called a rhizome, which attaches to surfaces in its turbulent habitat. This epiphytic growth habit—growing attached to objects rather than rooted in soil—dictates its specific care requirements. The African Water Fern has a slow growth rate, which results in less frequent maintenance once established.
Proper Planting and Initial Setup
The most important step is ensuring the rhizome is never buried in the substrate, as this will cause it to rot and the plant to fail. The rhizome requires direct exposure to the water column to access oxygen and nutrients for survival. Instead of planting, the African Water Fern must be attached to hardscape, such as driftwood, porous rock, or lava stone.
Attachment methods include using cotton thread, fishing line, or plant-safe super glue to secure the rhizome firmly to the surface. The fern’s fine roots will naturally adhere to the material within a few weeks, allowing temporary restraints to be removed if desired. Placing the plant in a location with good water flow helps expedite this attachment process and aids acclimation.
Essential Environmental Parameters for Growth
The African Water Fern thrives under low to moderate lighting conditions, which mimics the shaded areas it occupies in its native riverine environment. Too much light can stress the plant and, more commonly, trigger the growth of stubborn green algae on its slow-growing leaves, which can block light and hinder photosynthesis. A photoperiod of six to eight hours of consistent light is generally sufficient for healthy growth.
Maintaining clean, moving water is also important, as the plant naturally benefits from high oxygen levels and consistent current. The ideal water temperature range is between 68°F and 78°F (20°C to 26°C), as temperatures outside this window can slow growth or cause stress. Regarding water chemistry, the fern prefers soft, slightly acidic to neutral water, with a pH range of 6.0 to 7.5 being optimal.
The plant is primarily a water column feeder, drawing most of its nutrition directly from the surrounding water rather than through its attachment roots. While it is a slow grower and can survive without supplemental carbon dioxide (CO2) injection, providing CO2 can significantly enhance its growth rate and density. If CO2 is not used, a balanced liquid fertilizer containing essential micronutrients, particularly iron, should be applied regularly to ensure the plant receives adequate nutrition.
Long-Term Maintenance and Troubleshooting
Once the African Water Fern is established, maintenance involves periodic pruning. Old, damaged, or algae-covered leaves should be trimmed near the rhizome using sharp scissors to prevent damage to the main stem. This targeted removal encourages the plant to put energy into new, healthy growth.
Propagation is achieved through the division of the rhizome once the plant has matured. Use a sharp blade to cut the rhizome into smaller segments, ensuring that each new section retains at least a few healthy leaves. These newly divided segments can then be attached to new hardscape using the same methods as the initial setup.
The most common issue encountered is “melt,” where leaves turn brown or black, often caused by burying the rhizome, poor water flow, or drastic changes in water parameters. If melt occurs, remove the affected leaves and check the rhizome to ensure it remains firm and green. Algae growth is another frequent concern, usually signaling that the lighting is too intense or the water is too nutrient-rich; reducing the light intensity or duration helps mitigate this problem.