Fertilising guide
How to fertilise Toothed Fly Bush (Roridula dentata)— schedule & NPK
Also called toothed fly bush.
More about toothed fly bush
About Toothed Fly Bush
Roridula dentata · also called toothed fly bush · houseplant
Roridula dentata is a resinous South African carnivorous shrub distinguished from R. gorgonias by its toothed leaf margins and slightly larger stature. Like its relative, it traps insects on sticky resin and relies on Pameridea bugs for digestion. Demanding in cultivation — strictly mineral-free water and high light are non-negotiable.
Growth habit: Upright branching woody shrub with toothed, resin-coated leaves
Watch for — Mineral burn from tap water: Even low-TDS tap water causes leaf-tip browning and progressive resin failure. Use only rainwater, distilled, or RO water exclusively — switching mid-problem can halt but not immediately reverse damage.
What fertiliser toothed fly bush actually wants — and why
Toothed Fly Bush 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 toothed fly bush: 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 toothed fly bush, 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 toothed fly bush:
Soil feeding is not done. Leaf-surface nutrient acquisition via captured insects (and their symbiotic Pameridea bugs) is the natural mechanism. Specialist growers occasionally mist leaves with 1/8-strength fertiliser solution as a substitute in insect-free indoor environments. 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 toothed fly bush 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 toothed fly bush
Half strength is the safe default for toothed fly bush — 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 toothed fly bush first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the toothed fly bush watering schedule.
Signs you are over-feeding toothed fly bush
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for toothed fly bush:
- 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 toothed fly bush
- 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 toothed fly bush care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of toothed fly bush 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 toothed fly bush
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 toothed fly bush — frequently asked questions
What fertiliser does toothed fly bush 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. Toothed Fly Bush 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 toothed fly bush?
Soil feeding is not done. Leaf-surface nutrient acquisition via captured insects (and their symbiotic Pameridea bugs) is the natural mechanism. Specialist growers occasionally mist leaves with 1/8-strength fertiliser solution as a substitute in insect-free indoor environments. Soil feeding is not done. Leaf-surface nutrient acquisition via captured insects (and their symbiotic Pameridea bugs) is the natural mechanism. Specialist growers occasionally mist leaves with 1/8-strength fertiliser solution as a substitute in insect-free indoor environments. 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 toothed fly bush?
Half strength is the safe default for toothed fly bush — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding toothed fly bush 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 toothed fly bush 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 toothed fly bush?
Flush the pot of toothed fly bush 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
- Toothed Fly Bush care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water toothed fly bush — 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 calathea roseopicta 'cynthia'
- How to fertilise calathea roseopicta 'surprise star'
- How to fertilise calathea picturata 'argentea'
- All 6887 fertilising guides in the Growli library