Fertilising guide
How to fertilise Florist's Gloxinia (Sinningia speciosa)— schedule & NPK
Also called Florist's gloxinia, Brazilian gloxinia, Violet slipper gloxinia, Bright eyes, Gloxinia.
More about florist's gloxinia
About Florist's Gloxinia
Sinningia speciosa · also called Florist's gloxinia, Brazilian gloxinia · flowering
Florist's gloxinia (Sinningia speciosa) is a tuberous Brazilian gesneriad grown for velvety leaves and large, bell-shaped flowers in jewel tones. Give bright indirect light, evenly moist soil, warmth and high humidity, then a dry winter rest. The ASPCA lists it as non-toxic to cats, dogs and horses.
Growth habit: Low, mounding tuberous perennial with a rosette of large, soft, velvety leaves and upright, trumpet- to bell-shaped flowers held just above the foliage. Naturally dies back to its tuber for a dormant rest after flowering.
Watch for — Leggy growth, pale leaves: A sign of insufficient light. Move to a brighter spot with strong indirect light or supplement with a grow light, but avoid harsh direct sun.
What fertiliser florist's gloxinia actually wants — and why
Florist's Gloxinia 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 florist's gloxinia: 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 florist's gloxinia, 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 florist's gloxinia:
Feed every 1-2 weeks during active growth and flowering with a balanced or bloom-formula houseplant fertiliser diluted to half strength (a 15-15-15 type works well). Avoid high-phosphate, urea-heavy feeds. Stop feeding entirely as the plant winds down toward dormancy. Treat that as every 1-2 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 florist's gloxinia 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 florist's gloxinia
Half strength is the safe default for florist's gloxinia — 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 florist's gloxinia first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the florist's gloxinia watering schedule.
Signs you are over-feeding florist's gloxinia
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for florist's gloxinia:
- 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 florist's gloxinia
- 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 florist's gloxinia care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of florist's gloxinia 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 florist's gloxinia
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 florist's gloxinia — frequently asked questions
What fertiliser does florist's gloxinia 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. Florist's Gloxinia 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 florist's gloxinia?
Feed every 1-2 weeks during active growth and flowering with a balanced or bloom-formula houseplant fertiliser diluted to half strength (a 15-15-15 type works well). Avoid high-phosphate, urea-heavy feeds. Stop feeding entirely as the plant winds down toward dormancy. Feed every 1-2 weeks during active growth and flowering with a balanced or bloom-formula houseplant fertiliser diluted to half strength (a 15-15-15 type works well). Avoid high-phosphate, urea-heavy feeds. Stop feeding entirely as the plant winds down toward dormancy. Treat that as every 1-2 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 florist's gloxinia?
Half strength is the safe default for florist's gloxinia — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding florist's gloxinia 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 florist's gloxinia 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 florist's gloxinia?
Flush the pot of florist's gloxinia 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
- Florist's Gloxinia care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water florist's gloxinia — 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 peace lily
- How to fertilise bird of paradise
- How to fertilise hoya
- All 609 fertilising guides in the Growli library