Fertilising guide
How to fertilise Serissa Bonsai (Serissa japonica)— schedule & NPK
Also called tree of a thousand stars, snowrose bonsai, Japanese serissa.
More about serissa bonsai
About Serissa Bonsai
Serissa japonica · also called tree of a thousand stars, snowrose bonsai · houseplant
Serissa, the tree of a thousand stars, is a fine-twigged evergreen grown as bonsai for its tiny dark leaves and profusion of small white (sometimes pink) star flowers through the warmer months. It is rewarding but temperamental, dropping leaves at the slightest change in light, water or position. It needs bright light, steady warmth, even moisture and humidity.
Growth habit: Dense, twiggy evergreen dwarf shrub trained as bonsai; fine ramification, small leaves and pale knobbly bark, smothered in small star-shaped flowers over a long season.
What fertiliser serissa bonsai actually wants — and why
Serissa 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 serissa 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 serissa 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 serissa bonsai:
Feed every 2-4 weeks during spring and summer with a balanced liquid bonsai fertiliser at half to full strength, reducing in winter. Steady feeding supports the long flowering season and recovery after the frequent light pruning bonsai require. 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 serissa 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 serissa bonsai
Half strength is the safe default for serissa 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 serissa bonsai first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the serissa bonsai watering schedule.
Signs you are over-feeding serissa bonsai
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for serissa 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 serissa 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 serissa bonsai care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of serissa 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 serissa 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 serissa bonsai — frequently asked questions
What fertiliser does serissa 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. Serissa 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 serissa bonsai?
Feed every 2-4 weeks during spring and summer with a balanced liquid bonsai fertiliser at half to full strength, reducing in winter. Steady feeding supports the long flowering season and recovery after the frequent light pruning bonsai require. Feed every 2-4 weeks during spring and summer with a balanced liquid bonsai fertiliser at half to full strength, reducing in winter. Steady feeding supports the long flowering season and recovery after the frequent light pruning bonsai require. 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 serissa bonsai?
Half strength is the safe default for serissa bonsai — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding serissa 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 serissa 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 serissa bonsai?
Flush the pot of serissa 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
- Serissa Bonsai care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water serissa 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