Fertilising guide
How to fertilise Alocasia Infernalis (Alocasia infernalis)— schedule & NPK
Also called Black Magic jewel alocasia, infernal alocasia.
More about alocasia infernalis
About Alocasia Infernalis
Alocasia infernalis · also called Black Magic jewel alocasia, infernal alocasia · tropical
Alocasia infernalis, the 'Black Magic' jewel alocasia, is a small Bornean species prized for near-black leaves with a metallic blue-green to deep-red sheen. A compact corm-forming collector's plant, it thrives in cabinet conditions: bright indirect light, warmth, and very high humidity. Like other jewel alocasias it rots easily, so an airy medium and careful watering are essential.
Growth habit: Compact, slow-growing corm-forming aroid that produces a few upright, glossy near-black leaves; stays small and tidy, ideal for enclosed grows.
What fertiliser alocasia infernalis actually wants — and why
Alocasia Infernalis is a genuinely hungry tropical — in bright warmth it pushes growth fast and rewards a regular half-strength balanced feed all season.
A balanced liquid feed (even N-P-K) or a slightly nitrogen-leaning foliage feed — this is a big-leaved foliage plant putting on real size, so it wants steady nitrogen for lush leaves, not a bloom 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 alocasia infernalis: 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 alocasia infernalis, 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 alocasia infernalis:
Feed every 3-4 weeks in active growth with a dilute balanced fertiliser at quarter to half strength, or a hydroponic nutrient if in LECA. The small root system burns easily, so keep feeds weak and stop in winter. For a fast grower like this that means feeding regularly — about every 3-4 weeks — right through spring through early autumn (roughly March to September), tapering off only as light drops in autumn.
The dormant-season rule matters more than the exact interval: skip feeding entirely when alocasia infernalis 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 alocasia infernalis
Half strength every feed is the sweet spot for alocasia infernalis: frequent enough to fuel fast growth, dilute enough that it never scorches even when you feed often.
Feeding always goes onto already-damp soil, never dry roots — water alocasia infernalis first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the alocasia infernalis watering schedule.
Signs you are over-feeding alocasia infernalis
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for alocasia infernalis:
- Brown, scorched leaf tips and margins despite correct watering.
- A white salt crust on the soil or around the pot edge.
- Sudden leaf yellowing and drop shortly after a strong feed.
- Soft, weak, over-stretched growth that cannot support itself.
Signs you are under-feeding alocasia infernalis
- New leaves coming in noticeably smaller than older ones.
- Pale, yellow-green older leaves and slow growth through peak summer.
- A general loss of vigour and gloss in a plant that should be racing away.
If the symptoms point at watering, light or roots rather than nutrition, the full alocasia infernalis care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Because you feed often, salts accumulate faster — flush the pot of alocasia infernalis with plain water until it drains freely roughly every month through the feeding season to keep the root zone clean.
Organic vs synthetic feeds for alocasia infernalis
Organic options
A diluted seaweed or fish-and-seaweed feed plus a yearly top-dress of worm castings supports fast growth without burn risk. UK: Westland seaweed or Baby Bio Organic; US: Neptune's Harvest or Espoma Indoor!.
Synthetic / liquid feeds
A balanced houseplant liquid at half strength applied frequently — UK: Baby Bio, Phostrogen or Westland Houseplant Feed; US: Miracle-Gro Indoor Plant Food or Dyna-Gro Foliage-Pro for steady leafy growth.
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 alocasia infernalis — frequently asked questions
What fertiliser does alocasia infernalis need?
A balanced liquid feed (even N-P-K) or a slightly nitrogen-leaning foliage feed — this is a big-leaved foliage plant putting on real size, so it wants steady nitrogen for lush leaves, not a bloom formula. Alocasia Infernalis is a genuinely hungry tropical — in bright warmth it pushes growth fast and rewards a regular half-strength balanced feed all season.
How often should I feed alocasia infernalis?
Feed every 3-4 weeks in active growth with a dilute balanced fertiliser at quarter to half strength, or a hydroponic nutrient if in LECA. The small root system burns easily, so keep feeds weak and stop in winter. Feed every 3-4 weeks in active growth with a dilute balanced fertiliser at quarter to half strength, or a hydroponic nutrient if in LECA. The small root system burns easily, so keep feeds weak and stop in winter. For a fast grower like this that means feeding regularly — about every 3-4 weeks — right through spring through early autumn (roughly March to September), tapering off only as light drops in autumn.
What strength of feed for alocasia infernalis?
Half strength every feed is the sweet spot for alocasia infernalis: frequent enough to fuel fast growth, dilute enough that it never scorches even when you feed often.
What does over-feeding alocasia infernalis look like?
Brown, scorched leaf tips and margins despite correct watering. A white salt crust on the soil or around the pot edge. Sudden leaf yellowing and drop shortly after a strong feed. Soft, weak, over-stretched growth that cannot support itself. The mistake here is the opposite of most houseplants: under-feeding a fast tropical in peak season starves it, leaving small, pale new leaves and slow growth — but full-strength doses still burn it, so feed often and weak, not occasionally and strong.
Should I flush the soil of alocasia infernalis?
Because you feed often, salts accumulate faster — flush the pot of alocasia infernalis with plain water until it drains freely roughly every month through the feeding season to keep the root zone clean.
Keep reading
- Alocasia Infernalis care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water alocasia infernalis — 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 2464 fertilising guides in the Growli library