Fertilising guide
How to fertilise Reitz's sinningia (Sinningia reitzii)— schedule & NPK
Also called Reitz's sinningia.
More about reitz's sinningia
About Reitz's sinningia
Sinningia reitzii · also called Reitz's sinningia · flowering
Sinningia reitzii is a tuberous Brazilian gesneriad bearing vivid scarlet tubular flowers on upright stems above soft, hairy foliage. Named after the Brazilian botanist Raulino Reitz, it is a compact grower suited to bright windowsills. Like all sinningias, it undergoes a winter dormancy during which watering should be withdrawn.
Growth habit: Compact upright tuberous perennial with seasonal dormancy
What fertiliser reitz's sinningia actually wants — and why
Reitz's 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 reitz's 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 reitz's 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 reitz's sinningia:
Apply a balanced liquid fertiliser at half strength (e.g. 20-20-20) every 2 weeks from active growth onset through the end of flowering. A high-potassium feed (tomato-type) for the final 4 weeks before dormancy can help harden stems. Stop feeding completely in autumn. Treat that as every 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 reitz's 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 reitz's sinningia
Half strength is the safe default for reitz's 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 reitz's sinningia first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the reitz's sinningia watering schedule.
Signs you are over-feeding reitz's sinningia
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for reitz's 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 reitz's 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 reitz's sinningia care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of reitz's 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 reitz's 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 reitz's sinningia — frequently asked questions
What fertiliser does reitz's 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. Reitz's 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 reitz's sinningia?
Apply a balanced liquid fertiliser at half strength (e.g. 20-20-20) every 2 weeks from active growth onset through the end of flowering. A high-potassium feed (tomato-type) for the final 4 weeks before dormancy can help harden stems. Stop feeding completely in autumn. Apply a balanced liquid fertiliser at half strength (e.g. 20-20-20) every 2 weeks from active growth onset through the end of flowering. A high-potassium feed (tomato-type) for the final 4 weeks before dormancy can help harden stems. Stop feeding completely in autumn. Treat that as every 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 reitz's sinningia?
Half strength is the safe default for reitz's sinningia — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding reitz's 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 reitz's 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 reitz's sinningia?
Flush the pot of reitz's 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
- Reitz's sinningia care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water reitz's 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 maxillaria tenuifolia
- How to fertilise maxillaria variabilis
- How to fertilise coelogyne cristata
- All 6887 fertilising guides in the Growli library