Fertilising guide
How to fertilise Sellow's Sinningia (Sinningia sellovii)— schedule & NPK
Also called Sellow's Sinningia, Hardy Red Gloxinia, Hardy Gloxinia.
More about sellow's sinningia
About Sellow's Sinningia
Sinningia sellovii · also called Sellow's Sinningia, Hardy Red Gloxinia · flowering
Sinningia sellovii is a tuberous perennial native to Brazil, Bolivia, Paraguay, and Uruguay, where it grows in rocky, open habitats. It produces tubular red to orange-red flowers attractive to hummingbirds and is one of the hardiest Sinningia species, tolerating light frost when its tuber is established in the ground. Allow the tuber to dry out and go dormant in cooler months — do not water during dormancy or the tuber will rot. According to the ASPCA, Sinningia species (closely related to Gloxinia) are listed as non-toxic to cats and dogs.
Growth habit: Upright tuberous perennial that dies back to a dormant tuber each winter and re-sprouts in spring.
What fertiliser sellow's sinningia actually wants — and why
Sellow'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 sellow'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 sellow'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 sellow's sinningia:
Feed every two weeks with a balanced liquid fertiliser during the active growing season (spring through summer); withhold feed during winter dormancy. 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 sellow'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 sellow's sinningia
Half strength is the safe default for sellow'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 sellow'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 sellow's sinningia watering schedule.
Signs you are over-feeding sellow's sinningia
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for sellow'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 sellow'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 sellow's sinningia care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of sellow'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 sellow'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 sellow's sinningia — frequently asked questions
What fertiliser does sellow'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. Sellow'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 sellow's sinningia?
Feed every two weeks with a balanced liquid fertiliser during the active growing season (spring through summer); withhold feed during winter dormancy. Feed every two weeks with a balanced liquid fertiliser during the active growing season (spring through summer); withhold feed during winter dormancy. 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 sellow's sinningia?
Half strength is the safe default for sellow'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 sellow'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 sellow'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 sellow's sinningia?
Flush the pot of sellow'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
- Sellow's Sinningia care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water sellow'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 tall goldenrod
- How to fertilise stiff goldenrod
- How to fertilise showy goldenrod
- All 10153 fertilising guides in the Growli library