Fertilising guide
How to fertilise Ctenanthe 'Amagris' (Ctenanthe burle-marxii 'Amagris')— schedule & NPK
Also called Ctenanthe Amagris.
More about ctenanthe 'amagris'
About Ctenanthe 'Amagris'
Ctenanthe burle-marxii 'Amagris' · also called Ctenanthe Amagris · houseplant
Ctenanthe burle-marxii 'Amagris', the fishbone prayer plant, has pale silvery-grey leaves crossed by dark green fishbone bars, with maroon undersides. It forms a low, bushy clump and folds its leaves at night. It thrives in bright indirect light with evenly moist filtered water and high humidity, reaching around 30-40 cm tall.
Growth habit: Low, bushy and clumping, spreading from a creeping rhizome with leaves carried on upright petioles that fold up at night.
What fertiliser ctenanthe 'amagris' actually wants — and why
Ctenanthe 'Amagris' 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 ctenanthe 'amagris': 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 ctenanthe 'amagris', 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 ctenanthe 'amagris':
Feed every 4 weeks in spring and summer with a balanced liquid fertiliser at half strength. It is salt-sensitive, so flush the soil periodically and stop feeding in autumn and winter when growth slows. Treat that as every 4 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 ctenanthe 'amagris' 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 ctenanthe 'amagris'
Half strength is the safe default for ctenanthe 'amagris' — 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 ctenanthe 'amagris' first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the ctenanthe 'amagris' watering schedule.
Signs you are over-feeding ctenanthe 'amagris'
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for ctenanthe 'amagris':
- 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 ctenanthe 'amagris'
- 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 ctenanthe 'amagris' care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of ctenanthe 'amagris' 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 ctenanthe 'amagris'
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 ctenanthe 'amagris' — frequently asked questions
What fertiliser does ctenanthe 'amagris' 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. Ctenanthe 'Amagris' 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 ctenanthe 'amagris'?
Feed every 4 weeks in spring and summer with a balanced liquid fertiliser at half strength. It is salt-sensitive, so flush the soil periodically and stop feeding in autumn and winter when growth slows. Feed every 4 weeks in spring and summer with a balanced liquid fertiliser at half strength. It is salt-sensitive, so flush the soil periodically and stop feeding in autumn and winter when growth slows. Treat that as every 4 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 ctenanthe 'amagris'?
Half strength is the safe default for ctenanthe 'amagris' — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding ctenanthe 'amagris' 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 ctenanthe 'amagris' 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 ctenanthe 'amagris'?
Flush the pot of ctenanthe 'amagris' 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
- Ctenanthe 'Amagris' care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water ctenanthe 'amagris' — 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 1284 fertilising guides in the Growli library