Repotting guide

When & how to repot Bolbitis heudelotii (Bolbitis heudelotii)

Also called African water fern, Congo water fern.

More about bolbitis heudelotii

About Bolbitis heudelotii

Bolbitis heudelotii · also called African water fern, Congo water fern · tropical

Bolbitis heudelotii, the African water fern, is a slow-growing rhizomatous fern grown submerged in freshwater aquariums. Its translucent, finely divided dark-green fronds rise from a creeping rhizome that must be attached to wood or rock, never buried. Native to fast African streams, it prefers cool, well-oxygenated, moving water and rewards patience with an elegant, lacy texture.

Mature size: Fronds typically 15-40 cm tall; a single rhizome spreads to 20-30 cm across over many months.

Watch for — Rhizome rot from burial: Planting the rhizome in substrate suffocates and rots it. Attach it to wood or rock with the rhizome fully exposed and only roots touching the surface.

How to tell bolbitis heudelotii needs repotting

Repotting on a calendar is less reliable than reading the plant. For bolbitis heudelotii, watch for these signs:

Roots creeping out of the drainage holes or matting tightly across the soil surface.
The rootball dries out within a day or two no matter how much you water.
Water channels straight down the gap between rootball and pot without wetting the centre.
Steady decline — thin growth, persistent crispy edges — that good humidity and watering have not fixed. Only then is the disturbance of a repot worth the risk for bolbitis heudelotii.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot bolbitis heudelotii

Every 1–2 years, disturbing the roots as little as possible. Bolbitis heudelotii's growth habit — slow-growing, rhizomatous epiphytic fern with a creeping rhizome producing arching, finely pinnate, semi-translucent dark-green fronds. — sets the pace. Bolbitis heudelotii, the African water fern, is a slow-growing rhizomatous fern grown submerged in freshwater aquariums. Its translucent, finely divided dark-green fronds rise from a creeping rhizome that must be attached to wood or rock, never buried. Native to fast African streams, it prefers cool, well-oxygenated, moving water and rewards patience with an elegant, lacy texture.

What size pot to step bolbitis heudelotii up to

Go up only one size and handle the rootball as little as possible. Bolbitis heudelotii resents root disturbance, so the goal is to slide the intact rootball into slightly more soil — not to tease, wash or prune the roots. A modest step up means less shock and a faster recovery.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot bolbitis heudelotii

Early spring, just as new growth restarts, is the ideal window for bolbitis heudelotii. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting bolbitis heudelotii

Keep disturbance to a minimum. Bolbitis heudelotii resents root disturbance, so the plan is to move the intact rootball — not to wash, tease or prune the roots.
Choose just one size up. Pick a pot only one size larger with drainage, and have moisture-retentive no substrate — epiphytic on rhizome ready.
Slide the rootball out whole. Water the day before, then ease bolbitis heudelotii out keeping the rootball intact. Gently free only the roots that are circling the very bottom.
Nestle it into fresh soil. Add a base layer of fresh mix, set the rootball in at the same depth, and backfill gently around the sides without packing hard.
Water and protect. Water in, then keep it warm, humid and out of direct sun for a few weeks while it re-roots. Expect a short sulk — that is normal.

Aftercare

Expect bolbitis heudelotii to sulk for a couple of weeks — that is normal after any root disturbance for this group. Keep it warm, humid and out of direct sun, water just enough to keep the mix lightly moist, and do not panic and overwater while it re-roots. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for bolbitis heudelotii

Bolbitis heudelotii wants no substrate — epiphytic on rhizome. Grown attached, not planted. Tie or glue the rhizome to driftwood or stone with the rhizome exposed; burying the rhizome causes rot. Roots grip the hardscape over time. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting bolbitis heudelotii — frequently asked questions

How often should you repot bolbitis heudelotii?

Every 1–2 years, disturbing the roots as little as possible for bolbitis heudelotii. Repot bolbitis heudelotii every 1–2 years, disturbing the roots as little as possible — it sulks for weeks if the rootball is teased apart. Slide it into one size up in spring with fresh no substrate — epiphytic on rhizome, keep it warm and humid afterwards, and never bare-root or hard-prune the roots.

What size pot does bolbitis heudelotii need?

When is the best time of year to repot bolbitis heudelotii?

Why does bolbitis heudelotii sulk after repotting?

Bolbitis heudelotii resents root disturbance, so a wilt or stall for a week or two after repotting is normal, not a failure. Minimise it by keeping the rootball intact, stepping up just one size, and keeping the plant warm, humid and out of direct sun while it re-roots.

Should you fertilise bolbitis heudelotii after repotting?

Not immediately. Wait about 4 weeks after repotting bolbitis heudelotii. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.