Fertilising guide
How to fertilise Case's Ixora (Ixora casei)— schedule & NPK
Also called Case's Ixora, Caroline Islands Ixora.
More about case's ixora
About Case's Ixora
Ixora casei · also called Case's Ixora, Caroline Islands Ixora · tropical
Case's Ixora is a rare tropical shrub native to the Caroline Islands of Micronesia, producing large corymbs of vivid red tubular flowers. Closely related to and sometimes confused with Ixora casei from Pohnpei, it is grown as an ornamental in Pacific Island gardens and specialist tropical collections worldwide, valued for its large flower clusters.
Growth habit: Upright, branching evergreen shrub
What fertiliser case's ixora actually wants — and why
Case's Ixora 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 case's ixora: 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 case's ixora, 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 case's ixora:
Use a slow-release acidic fertiliser (camellia or azalea formulation) every 6-8 weeks during active growth. Apply chelated iron supplements if interveinal chlorosis appears. Avoid high-phosphorus formulas; a balanced NPK with micronutrients suits this species best. Treat that as every 6-8 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 case's ixora 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 case's ixora
Half strength is the safe default for case's ixora — 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 case's ixora first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the case's ixora watering schedule.
Signs you are over-feeding case's ixora
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for case's ixora:
- 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 case's ixora
- 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 case's ixora care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of case's ixora 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 case's ixora
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 case's ixora — frequently asked questions
What fertiliser does case's ixora 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. Case's Ixora 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 case's ixora?
Use a slow-release acidic fertiliser (camellia or azalea formulation) every 6-8 weeks during active growth. Apply chelated iron supplements if interveinal chlorosis appears. Avoid high-phosphorus formulas; a balanced NPK with micronutrients suits this species best. Use a slow-release acidic fertiliser (camellia or azalea formulation) every 6-8 weeks during active growth. Apply chelated iron supplements if interveinal chlorosis appears. Avoid high-phosphorus formulas; a balanced NPK with micronutrients suits this species best. Treat that as every 6-8 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 case's ixora?
Half strength is the safe default for case's ixora — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding case's ixora 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 case's ixora 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 case's ixora?
Flush the pot of case's ixora 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
- Case's Ixora care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water case's ixora — 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 açaí palm
- How to fertilise mamoncillo
- How to fertilise kiwano
- All 6887 fertilising guides in the Growli library