Fertilising guide
How to fertilise African Crossandra (Crossandra nilotica)— schedule & NPK
Also called African Crossandra, Red Firecracker Flower, Red Crossandra.
More about african crossandra
About African Crossandra
Crossandra nilotica · also called African Crossandra, Red Firecracker Flower · flowering
A compact African shrub distinct from the Indian firecracker flower, bearing narrow leaves and coral-to-brick-red flower spikes. It tolerates drier air better than its relatives but demands bright light and consistent warmth to bloom. Water evenly, avoid cold draughts, and feed lightly through the growing season for reliable flowering.
Growth habit: Upright, bushy, evergreen perennial sub-shrub
What fertiliser african crossandra actually wants — and why
African Crossandra 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 african crossandra: 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 african crossandra, 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 african crossandra:
Feed with a balanced liquid fertiliser (e.g., 10-10-10) at half strength every 2–3 weeks from spring through early autumn. Withhold feed in winter when growth slows. 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 african crossandra 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 african crossandra
Half strength is the safe default for african crossandra — 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 african crossandra first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the african crossandra watering schedule.
Signs you are over-feeding african crossandra
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for african crossandra:
- 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 african crossandra
- 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 african crossandra care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of african crossandra 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 african crossandra
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 african crossandra — frequently asked questions
What fertiliser does african crossandra 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. African Crossandra 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 african crossandra?
Feed with a balanced liquid fertiliser (e.g., 10-10-10) at half strength every 2–3 weeks from spring through early autumn. Withhold feed in winter when growth slows. Feed with a balanced liquid fertiliser (e.g., 10-10-10) at half strength every 2–3 weeks from spring through early autumn. Withhold feed in winter when growth slows. 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 african crossandra?
Half strength is the safe default for african crossandra — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding african crossandra 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 african crossandra 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 african crossandra?
Flush the pot of african crossandra 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
- African Crossandra care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water african crossandra — 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 confederate rose
- How to fertilise japanese spirea
- How to fertilise gold mound spirea
- All 8452 fertilising guides in the Growli library