Fertilising guide
How to fertilise Common African Violet (Saintpaulia ionantha)— schedule & NPK
Also called African Violet, Usambara Violet, Cape Marigold (trade misnomer, avoid).
More about common african violet
About Common African Violet
Saintpaulia ionantha · also called African Violet, Usambara Violet · houseplant
Common African Violet is the world's most popular flowering houseplant, producing velvety rosettes of dark green leaves and clusters of cheerful violet, purple, pink, or white flowers almost year-round indoors. It thrives under controlled warmth, indirect light, and consistent moisture. ASPCA non-toxic — completely safe for pets.
Growth habit: Compact, stemless rosette-forming gesneriad
Watch for — Failure to rebloom: Caused by insufficient light, wrong pot size, or lack of fertiliser. Move to a brighter position, repot if root-bound beyond snug, and resume regular feeding.
What fertiliser common african violet actually wants — and why
Common African Violet is feeding to flower, not to grow leaves — it needs a higher-phosphorus / specialist bloom feed, given little and often, to set and hold its display.
A higher-phosphorus "bloom" formula or a species-specific feed (orchid food, African violet food, or a tomato-style high-potash/phosphorus liquid). A high-nitrogen general feed gives you lush leaves and almost no flowers.
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 common african violet: 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 common african violet, 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 common african violet:
Feed every 2-4 weeks with a dedicated African violet fertiliser (high phosphorus, e.g. 7-9-5 NPK) diluted to half strength throughout the year. A consistent low-dose feeding approach outperforms heavy occasional feeds. Flush the soil monthly to prevent fertiliser salt build-up. The pattern that matters: feed little and often through active growth and budding — every 2-4 weeks — and ease right off during the rest period that triggers the next flush.
The dormant-season rule matters more than the exact interval: skip feeding entirely when common african violet 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 common african violet
Very dilute — quarter strength, the classic "weakly, weekly" approach for common african violet. These plants have fine roots that scorch easily and a steady trickle beats an occasional strong dose for flowering.
Feeding always goes onto already-damp soil, never dry roots — water common african violet first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the common african violet watering schedule.
Signs you are over-feeding common african violet
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for common african violet:
- Lush green leaves but few or no flowers (too much nitrogen).
- Brown, scorched leaf tips and edges — a classic fine-root burn.
- White salt crust on the medium or pot, and stalled buds.
- Bud blast: buds forming then shrivelling and dropping.
Signs you are under-feeding common african violet
- Sparse or no flowering despite good light and the right season.
- Smaller, paler new leaves and a generally weak, tired plant.
- Flowers that are smaller or fade faster than they should.
If the symptoms point at watering, light or roots rather than nutrition, the full common african violet care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Specialist and bloom feeds leave salts that scorch fine roots — flush common african violet thoroughly with plain water until it runs clear every 4-6 weeks in the feeding season, and always between feeds for orchids.
Organic vs synthetic feeds for common african violet
Organic options
Gentler options exist: a dilute seaweed feed (mildly potassium-rich) or worm-casting tea. UK: Westland seaweed, or a dilute tomato feed like Tomorite for bud-formers; US: Espoma Orchid! / Violet! or Neptune's Harvest. Lower burn risk, slower response.
Synthetic / liquid feeds
A species-matched bloom feed at quarter strength — UK: Baby Bio Orchid / African Violet food, or a high-potash Tomorite/Phostrogen for budding bloomers; US: Miracle-Gro Orchid or Bloom Booster, Schultz African Violet.
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 common african violet — frequently asked questions
What fertiliser does common african violet need?
A higher-phosphorus "bloom" formula or a species-specific feed (orchid food, African violet food, or a tomato-style high-potash/phosphorus liquid). A high-nitrogen general feed gives you lush leaves and almost no flowers. Common African Violet is feeding to flower, not to grow leaves — it needs a higher-phosphorus / specialist bloom feed, given little and often, to set and hold its display.
How often should I feed common african violet?
Feed every 2-4 weeks with a dedicated African violet fertiliser (high phosphorus, e.g. 7-9-5 NPK) diluted to half strength throughout the year. A consistent low-dose feeding approach outperforms heavy occasional feeds. Flush the soil monthly to prevent fertiliser salt build-up. Feed every 2-4 weeks with a dedicated African violet fertiliser (high phosphorus, e.g. 7-9-5 NPK) diluted to half strength throughout the year. A consistent low-dose feeding approach outperforms heavy occasional feeds. Flush the soil monthly to prevent fertiliser salt build-up. The pattern that matters: feed little and often through active growth and budding — every 2-4 weeks — and ease right off during the rest period that triggers the next flush.
What strength of feed for common african violet?
Very dilute — quarter strength, the classic "weakly, weekly" approach for common african violet. These plants have fine roots that scorch easily and a steady trickle beats an occasional strong dose for flowering.
What does over-feeding common african violet look like?
Lush green leaves but few or no flowers (too much nitrogen). Brown, scorched leaf tips and edges — a classic fine-root burn. White salt crust on the medium or pot, and stalled buds. Bud blast: buds forming then shrivelling and dropping. Using an ordinary high-nitrogen houseplant feed on common african violet is the headline mistake — you get a healthy-looking plant that simply refuses to bloom. The second is feeding through the rest period and breaking the dormancy cue it needs to set buds.
Should I flush the soil of common african violet?
Specialist and bloom feeds leave salts that scorch fine roots — flush common african violet thoroughly with plain water until it runs clear every 4-6 weeks in the feeding season, and always between feeds for orchids.
Keep reading
- Common African Violet care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water common african violet — 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 peperomia viridispica
- How to fertilise peperomia crassifolia
- How to fertilise peperomia 'quito'
- All 11687 fertilising guides in the Growli library