Propagating African Water Fern 'Mini' (Bolbitis heudelotii 'Mini')

How to propagate the compact African water fern 'Mini' by dividing its rhizome and tying or glueing the sections to wood, with soft acidic water and good flow for slow but steady growth.

Overview

African water fern (Bolbitis heudelotii) is an aquatic fern native to subtropical and tropical Africa, from Ethiopia west to Senegal and down to northern South Africa. It attaches to surfaces with threadlike rootlets extending from its rhizome rather than true roots, and is best grown secured to a piece of wood rather than planted directly in the substrate. The 'Mini' selection is a smaller, more compact form but shares the same rhizome biology.

In nature the water over its sandy or rocky bottoms is fast-moving, very clean, not very hard and slightly acidic — conditions that guide how you raise new divisions.

Propagation Method (Rhizome Division)

Bolbitis is propagated by division of the rhizome. The plant has a horizontal, branch-like rhizome that should not be covered up; you cut it into sections, each retaining rootlets and fronds. Cutting all the leaves off a rhizome and retying it to wood can even promote three to four new rhizomes to start from the mother piece, though regrowth then takes longer.

Step-by-Step

1. Lift the mother plant off its wood and rinse away debris.
2. Cut the horizontal rhizome into sections with clean scissors, keeping rootlets and a few fronds on each.
3. Tie each section to driftwood or rock with sewing thread, or use a small amount of super glue gel.
4. Lay the rhizome on top of the hardscape so it stays fully exposed.
5. Place the wood where there is good water flow and return it to the tank.

Conditions for Healthy Growth

Keep temperatures around 20–28 °C and a slightly acidic to neutral pH (roughly 5.0–7.0), with soft, clean water. The fern tolerates a wide range of light levels but does best in flowing water that mimics its native fast-moving streams. CO2 is not required, though stable, well-oxygenated conditions help the slow-growing divisions take hold.

Maintenance

Give the plant room — Bolbitis is intolerant of being crowded and of fish excreta, so maintain clean water and avoid packing it against other plants. As the rootlets wrap the hardscape the attachment becomes secure and any thread can be removed.

Common Challenges

This is a slow-growing plant, so expect patience before divisions visibly expand. Crowding, dirty water and high fish loads stress it, and burying the rhizome is the classic fatal mistake. Stagnant water also holds it back — restore flow if new fronds stall.