Fertilising guide
How to fertilise Changing Tibouchina (Tibouchina mutabilis)— schedule & NPK
Also called Changing Tibouchina, Manacá da Serra, Princess Flower, Colour-changing Glorybush.
More about changing tibouchina
About Changing Tibouchina
Tibouchina mutabilis · also called Changing Tibouchina, Manacá da Serra · tropical
Tibouchina mutabilis is a large, evergreen shrub or small tree from the Atlantic Forest highlands of south-eastern Brazil, celebrated for its remarkable flower colour transformation — blooms open white and gradually mature through lavender to deep purple-violet, so a single plant carries three colours simultaneously. Native to cooler montane elevations, it tolerates slightly cooler conditions than other Tibouchina species. Full sun and moist, acidic, well-draining soil are the key requirements. Tibouchina mutabilis has no documented toxic principles and is not listed as toxic by major poison-control authorities.
Growth habit: Upright, multi-branched, evergreen shrub or small tree with slightly arching stems and velvety, oval-to-oblong leaves.
What fertiliser changing tibouchina actually wants — and why
Changing Tibouchina 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 changing tibouchina: 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 changing tibouchina, 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 changing tibouchina:
Feed with a balanced slow-release fertiliser in spring, then switch to a high-potash liquid fertiliser every two weeks from early summer through autumn to sustain the long flowering season. 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 changing tibouchina 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 changing tibouchina
Half strength is the safe default for changing tibouchina — 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 changing tibouchina first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the changing tibouchina watering schedule.
Signs you are over-feeding changing tibouchina
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for changing tibouchina:
- 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 changing tibouchina
- 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 changing tibouchina care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of changing tibouchina 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 changing tibouchina
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 changing tibouchina — frequently asked questions
What fertiliser does changing tibouchina 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. Changing Tibouchina 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 changing tibouchina?
Feed with a balanced slow-release fertiliser in spring, then switch to a high-potash liquid fertiliser every two weeks from early summer through autumn to sustain the long flowering season. Feed with a balanced slow-release fertiliser in spring, then switch to a high-potash liquid fertiliser every two weeks from early summer through autumn to sustain the long flowering season. 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 changing tibouchina?
Half strength is the safe default for changing tibouchina — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding changing tibouchina 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 changing tibouchina 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 changing tibouchina?
Flush the pot of changing tibouchina 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
- Changing Tibouchina care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water changing tibouchina — 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 alocasia infernalis
- How to fertilise alocasia platyphylla
- How to fertilise alocasia sinuata
- All 10153 fertilising guides in the Growli library