Fertilising guide
How to fertilise Anchomanes giganteus (Anchomanes giganteus)— schedule & NPK
Also called giant anchomanes, West African arum.
More about anchomanes giganteus
About Anchomanes giganteus
Anchomanes giganteus · also called giant anchomanes, West African arum · tropical
Anchomanes giganteus is a towering tropical African aroid, even more imposing than A. difformis, producing one immense, intricately divided leaf on a tall, spiny, marbled stalk from a massive underground rhizome. A seasonal grower from West and Central African forest, it dies back fully in the dry season. Its sheer scale makes it a dramatic specimen for large warm conservatories.
Growth habit: Very large tuberous/rhizomatous perennial producing a single giant, deeply dissected leaf on a tall spiny mottled petiole each season, dying back to a massive rhizome.
What fertiliser anchomanes giganteus actually wants — and why
Anchomanes giganteus 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 anchomanes giganteus: 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 anchomanes giganteus, 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 anchomanes giganteus:
Feed every 2-3 weeks with a balanced liquid fertiliser through active growth to power the enormous leaf, then stop entirely as the plant enters dormancy. Treat that as every 2-3 weeks 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 anchomanes giganteus 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 anchomanes giganteus
Half strength is the safe default for anchomanes giganteus — 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 anchomanes giganteus first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the anchomanes giganteus watering schedule.
Signs you are over-feeding anchomanes giganteus
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for anchomanes giganteus:
- 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 anchomanes giganteus
- 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 anchomanes giganteus care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of anchomanes giganteus 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 anchomanes giganteus
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 anchomanes giganteus — frequently asked questions
What fertiliser does anchomanes giganteus 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. Anchomanes giganteus 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 anchomanes giganteus?
Feed every 2-3 weeks with a balanced liquid fertiliser through active growth to power the enormous leaf, then stop entirely as the plant enters dormancy. Feed every 2-3 weeks with a balanced liquid fertiliser through active growth to power the enormous leaf, then stop entirely as the plant enters dormancy. Treat that as every 2-3 weeks 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 anchomanes giganteus?
Half strength is the safe default for anchomanes giganteus — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding anchomanes giganteus 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 anchomanes giganteus 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 anchomanes giganteus?
Flush the pot of anchomanes giganteus 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
- Anchomanes giganteus care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water anchomanes giganteus — 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 monstera
- How to fertilise pothos
- How to fertilise fiddle leaf fig
- All 5561 fertilising guides in the Growli library