Fertilising guide
How to fertilise Calathea Picturata (Goeppertia picturata)— schedule & NPK
Also called silver calathea, Argentea calathea.
More about calathea picturata
About Calathea Picturata
Goeppertia picturata · also called silver calathea, Argentea calathea · houseplant
Calathea Picturata (Goeppertia picturata), including the 'Argentea' form, is a striking prayer plant with broad leaves washed almost entirely silvery-pewter inside a slim dark-green margin, over wine-red undersides. Compact and pet-safe, it brings a metallic glow to bright corners and asks for warmth, high humidity, and pure water.
Growth habit: Compact, clumping rosette of broad upright leaves; folds at night to show red undersides.
Watch for — Browning leaf edges: Low humidity or tap-water minerals affect the pale tissue fast. Use distilled/rainwater and raise humidity.
What fertiliser calathea picturata actually wants — and why
Calathea Picturata 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 calathea picturata: 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 calathea picturata, 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 calathea picturata:
Feed monthly through spring and summer with a balanced fertiliser at half strength. Marantaceae are salt-sensitive, so dilute well, flush the pot occasionally, and stop feeding in winter. Treat that as monthly 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 calathea picturata 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 calathea picturata
Half strength is the safe default for calathea picturata — 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 calathea picturata first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the calathea picturata watering schedule.
Signs you are over-feeding calathea picturata
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for calathea picturata:
- 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 calathea picturata
- 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 calathea picturata care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of calathea picturata 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 calathea picturata
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 calathea picturata — frequently asked questions
What fertiliser does calathea picturata 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. Calathea Picturata 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 calathea picturata?
Feed monthly through spring and summer with a balanced fertiliser at half strength. Marantaceae are salt-sensitive, so dilute well, flush the pot occasionally, and stop feeding in winter. Feed monthly through spring and summer with a balanced fertiliser at half strength. Marantaceae are salt-sensitive, so dilute well, flush the pot occasionally, and stop feeding in winter. Treat that as monthly 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 calathea picturata?
Half strength is the safe default for calathea picturata — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding calathea picturata 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 calathea picturata 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 calathea picturata?
Flush the pot of calathea picturata 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
- Calathea Picturata care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water calathea picturata — 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 snake plant
- How to fertilise dracaena
- How to fertilise peperomia
- All 2464 fertilising guides in the Growli library