Fertilising guide
How to fertilise Congo Anubias (Anubias heterophylla)— schedule & NPK
Also called Variable-leaf Anubias, African Water Fern Anubias.
More about congo anubias
About Congo Anubias
Anubias heterophylla · also called Variable-leaf Anubias, African Water Fern Anubias · tropical
One of the largest Anubias species, native to central Africa, producing broad, lance-shaped dark green leaves that can reach 35 cm in length. It makes a dramatic background or midground statement in large aquariums. Like all Anubias it demands rhizome attachment to hardscape, not substrate burial. Slow-growing and exceptionally hardy. As an aroid it is toxic to pets.
Growth habit: Large rhizomatous aquatic; slow-growing, spreading by rhizome extension
What fertiliser congo anubias actually wants — and why
Congo Anubias is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for congo anubias: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed congo anubias, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For congo anubias:
Supplement with a balanced liquid fertiliser weekly; iron is especially important for deep green leaf colouration. CO2 injection is beneficial but not required. Root tabs in nearby substrate have limited benefit for rhizome-attached plants. Treat that as weekly between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when congo anubias is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for congo anubias
Half strength is the safe default for congo anubias — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water congo anubias first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the congo anubias watering schedule.
Signs you are over-feeding congo anubias
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for congo anubias:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding congo anubias
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full congo anubias care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of congo anubias with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for congo anubias
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising congo anubias — frequently asked questions
What fertiliser does congo anubias need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Congo Anubias is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed congo anubias?
Supplement with a balanced liquid fertiliser weekly; iron is especially important for deep green leaf colouration. CO2 injection is beneficial but not required. Root tabs in nearby substrate have limited benefit for rhizome-attached plants. Supplement with a balanced liquid fertiliser weekly; iron is especially important for deep green leaf colouration. CO2 injection is beneficial but not required. Root tabs in nearby substrate have limited benefit for rhizome-attached plants. Treat that as weekly between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for congo anubias?
Half strength is the safe default for congo anubias — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding congo anubias look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding congo anubias year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of congo anubias?
Flush the pot of congo anubias with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Congo Anubias care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water congo anubias — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise neoregelia 'painted lady'
- How to fertilise aechmea blanchetiana
- How to fertilise aechmea gamosepala
- All 11687 fertilising guides in the Growli library