Fertilising guide
How to fertilise Red Angel's Trumpet (Brugmansia sanguinea)— schedule & NPK
Also called Red Angel's Trumpet, Blood-red Angel's Trumpet, Floripondio.
More about red angel's trumpet
About Red Angel's Trumpet
Brugmansia sanguinea · also called Red Angel's Trumpet, Blood-red Angel's Trumpet · flowering
Brugmansia sanguinea is a distinctive Andean species bearing unscented tubular flowers that are vivid orange-red at the tip fading to yellow-green at the base. Uniquely among Brugmansias it prefers cool highland conditions rather than tropical heat. All parts are severely toxic. Suited to cooler gardens or frost-free containers in temperate climates.
Growth habit: Upright, branching evergreen to semi-evergreen shrub or small tree
Watch for — Leaf yellowing (chlorosis): Often caused by iron or magnesium deficiency in alkaline soils; acidify with sulphur chips or use an ericaceous liquid feed to correct micronutrient uptake.
What fertiliser red angel's trumpet actually wants — and why
Red Angel's Trumpet 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 red angel's trumpet: 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 red angel's trumpet, 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 red angel's trumpet:
Feed every 2 weeks during the growing season with a balanced liquid fertiliser, then switch to a high-potassium formula as flower buds form. This cooler-growing species benefits from slightly lower nitrogen than tropical Brugmansias. Cease feeding in autumn and winter. 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 red angel's trumpet 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 red angel's trumpet
Half strength is the safe default for red angel's trumpet — 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 red angel's trumpet first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the red angel's trumpet watering schedule.
Signs you are over-feeding red angel's trumpet
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for red angel's trumpet:
- 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 red angel's trumpet
- 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 red angel's trumpet care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of red angel's trumpet 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 red angel's trumpet
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 red angel's trumpet — frequently asked questions
What fertiliser does red angel's trumpet 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. Red Angel's Trumpet 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 red angel's trumpet?
Feed every 2 weeks during the growing season with a balanced liquid fertiliser, then switch to a high-potassium formula as flower buds form. This cooler-growing species benefits from slightly lower nitrogen than tropical Brugmansias. Cease feeding in autumn and winter. Feed every 2 weeks during the growing season with a balanced liquid fertiliser, then switch to a high-potassium formula as flower buds form. This cooler-growing species benefits from slightly lower nitrogen than tropical Brugmansias. Cease feeding in autumn and winter. 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 red angel's trumpet?
Half strength is the safe default for red angel's trumpet — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding red angel's trumpet 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 red angel's trumpet 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 red angel's trumpet?
Flush the pot of red angel's trumpet 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
- Red Angel's Trumpet care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water red angel's trumpet — 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 brunnera macrophylla
- How to fertilise agastache 'blue fortune'
- How to fertilise veronicastrum virginicum 'fascination'
- All 6887 fertilising guides in the Growli library