Fertilising guide
How to fertilise Showy Sinningia (Sinningia conspicua)— schedule & NPK
Also called Showy Sinningia, Conspicuous Sinningia, Brazilian Foxglove.
More about showy sinningia
About Showy Sinningia
Sinningia conspicua · also called Showy Sinningia, Conspicuous Sinningia · flowering
Sinningia conspicua is a tuberous perennial native to Brazil, forming compact rosettes of soft, velvety, mid-green hairy leaves from which it produces upright spikes of large pale-to-mid-yellow tubular flowers with cinnamon or purple internal markings from early summer through to autumn. Its foxglove-like flowers have a subtle lemon fragrance and are comparatively easy to grow under glass or as a houseplant in bright filtered light. After flowering, allow the foliage to die back naturally and keep the tuber dry over winter. The ASPCA lists Sinningia (Gloxinia) as non-toxic to cats and dogs.
Growth habit: Compact rosette-forming tuberous perennial with upright flower spikes in summer.
What fertiliser showy sinningia actually wants — and why
Showy Sinningia 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 showy sinningia: 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 showy sinningia, 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 showy sinningia:
Feed every two to three weeks with a balanced liquid fertiliser from spring to early autumn; cease feeding once growth slows as days shorten. 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 showy sinningia 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 showy sinningia
Half strength is the safe default for showy sinningia — 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 showy sinningia first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the showy sinningia watering schedule.
Signs you are over-feeding showy sinningia
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for showy sinningia:
- 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 showy sinningia
- 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 showy sinningia care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of showy sinningia 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 showy sinningia
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 showy sinningia — frequently asked questions
What fertiliser does showy sinningia 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. Showy Sinningia 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 showy sinningia?
Feed every two to three weeks with a balanced liquid fertiliser from spring to early autumn; cease feeding once growth slows as days shorten. Feed every two to three weeks with a balanced liquid fertiliser from spring to early autumn; cease feeding once growth slows as days shorten. 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 showy sinningia?
Half strength is the safe default for showy sinningia — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding showy sinningia 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 showy sinningia 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 showy sinningia?
Flush the pot of showy sinningia 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
- Showy Sinningia care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water showy sinningia — 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 emperor tulip
- How to fertilise greig's tulip
- How to fertilise late tulip
- All 10153 fertilising guides in the Growli library