Fertilising guide
How to fertilise Ficus Retusa Bonsai (Ficus retusa)— schedule & NPK
Also called Taiwan ficus, banyan fig bonsai, retusa fig.
More about ficus retusa bonsai
About Ficus Retusa Bonsai
Ficus retusa · also called Taiwan ficus, banyan fig bonsai · houseplant
Ficus retusa is one of the most popular and forgiving indoor bonsai, valued for its thick swollen trunk, aerial roots and dense glossy leaves. A tropical fig, it tolerates lower light and irregular care better than most bonsai. Grown indoors year-round in temperate climates, it needs warmth, bright light, steady moisture and regular pruning to maintain shape.
Growth habit: Vigorous tropical fig trained as bonsai, forming a stout buttressed trunk and dense twiggy canopy; readily back-buds after pruning and produces aerial roots in humid conditions.
Watch for — Weak, etiolated growth: Pale, stretched shoots and large sparse leaves signal too little light; move to the brightest position and consider supplemental grow lights in winter.
What fertiliser ficus retusa bonsai actually wants — and why
Ficus Retusa Bonsai 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 ficus retusa bonsai: 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 ficus retusa bonsai, 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 ficus retusa bonsai:
Feed every 2-4 weeks through spring and summer with a balanced liquid bonsai or houseplant fertiliser at the recommended strength; reduce to roughly monthly in winter if growth continues indoors. Regular feeding supports the constant growth that pruning provokes. Treat that as every 2-4 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 ficus retusa bonsai 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 ficus retusa bonsai
Half strength is the safe default for ficus retusa bonsai — 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 ficus retusa bonsai first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the ficus retusa bonsai watering schedule.
Signs you are over-feeding ficus retusa bonsai
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for ficus retusa bonsai:
- 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 ficus retusa bonsai
- 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 ficus retusa bonsai care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of ficus retusa bonsai 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 ficus retusa bonsai
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 ficus retusa bonsai — frequently asked questions
What fertiliser does ficus retusa bonsai 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. Ficus Retusa Bonsai 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 ficus retusa bonsai?
Feed every 2-4 weeks through spring and summer with a balanced liquid bonsai or houseplant fertiliser at the recommended strength; reduce to roughly monthly in winter if growth continues indoors. Regular feeding supports the constant growth that pruning provokes. Feed every 2-4 weeks through spring and summer with a balanced liquid bonsai or houseplant fertiliser at the recommended strength; reduce to roughly monthly in winter if growth continues indoors. Regular feeding supports the constant growth that pruning provokes. Treat that as every 2-4 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 ficus retusa bonsai?
Half strength is the safe default for ficus retusa bonsai — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding ficus retusa bonsai 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 ficus retusa bonsai 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 ficus retusa bonsai?
Flush the pot of ficus retusa bonsai 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
- Ficus Retusa Bonsai care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water ficus retusa bonsai — 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 3899 fertilising guides in the Growli library