Fertilising guide
How to fertilise Ambarella (Spondias dulcis)— schedule & NPK
Also called Ambarella, June Plum, Golden Apple, Jew Plum, Polynesian Plum.
More about ambarella
About Ambarella
Spondias dulcis · also called Ambarella, June Plum · tropical
Ambarella is a fast-growing tropical tree producing crisp, tangy-sweet golden fruits eaten fresh when ripe or pickled and added to condiments when green. Native to Melanesia and widely cultivated across the tropics, it thrives in full sun with moderate moisture and grows with impressive speed, making it a rewarding fruit tree for tropical and subtropical gardens.
Growth habit: Fast-growing, deciduous to semi-evergreen tree with an upright then spreading canopy; can reach considerable height quickly
Watch for — Iron/micronutrient deficiency on alkaline soils: Interveinal chlorosis (yellowing between veins on new leaves) indicates iron or manganese deficiency, common when pH exceeds 7.0. Acidify soil with sulphur applications and apply chelated iron as a foliar spray or soil drench.
What fertiliser ambarella actually wants — and why
Ambarella 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 ambarella: 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 ambarella, 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 ambarella:
Apply a balanced tropical fruit fertiliser (e.g. 10-10-10) three times per year — spring, early summer, and early autumn in subtropical regions. Young trees benefit from more frequent light applications to support fast growth. Supplement with micronutrients (zinc, manganese) if leaf yellowing occurs. Treat that as sparingly through the growing season 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 ambarella 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 ambarella
Half strength is the safe default for ambarella — 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 ambarella first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the ambarella watering schedule.
Signs you are over-feeding ambarella
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for ambarella:
- 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 ambarella
- 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 ambarella care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of ambarella 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 ambarella
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 ambarella — frequently asked questions
What fertiliser does ambarella 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. Ambarella 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 ambarella?
Apply a balanced tropical fruit fertiliser (e.g. 10-10-10) three times per year — spring, early summer, and early autumn in subtropical regions. Young trees benefit from more frequent light applications to support fast growth. Supplement with micronutrients (zinc, manganese) if leaf yellowing occurs. Apply a balanced tropical fruit fertiliser (e.g. 10-10-10) three times per year — spring, early summer, and early autumn in subtropical regions. Young trees benefit from more frequent light applications to support fast growth. Supplement with micronutrients (zinc, manganese) if leaf yellowing occurs. Treat that as sparingly through the growing season 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 ambarella?
Half strength is the safe default for ambarella — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding ambarella 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 ambarella 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 ambarella?
Flush the pot of ambarella 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
- Ambarella care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water ambarella — 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 mamey sapote
- How to fertilise abiu
- How to fertilise black sapote
- All 8452 fertilising guides in the Growli library