Fertilising guide
How to fertilise Yellow Trumpetbush (Tecoma stans)— schedule & NPK
Also called Yellow Trumpetbush, Yellow Elder, Yellow Bells, Esperanza, Trumpetbush.
More about yellow trumpetbush
About Yellow Trumpetbush
Tecoma stans · also called Yellow Trumpetbush, Yellow Elder · tropical
A fast-growing evergreen shrub or small tree bearing clusters of bright yellow trumpet flowers nearly year-round in frost-free climates. Thrives in full sun with well-drained soil and excellent drought tolerance once established. Ideal for warm gardens, poolsides, and large containers. Best in USDA zones 9–11; bring under glass in cooler regions.
Growth habit: Multi-stemmed evergreen shrub or small tree with arching branches; fast-growing; can be trained to a single trunk
Watch for — Failure to flower: Usually caused by insufficient direct sunlight or over-feeding with nitrogen. Move to a sunnier position, reduce nitrogen, and apply a high-potassium feed to encourage blooming.
What fertiliser yellow trumpetbush actually wants — and why
Yellow Trumpetbush 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 yellow trumpetbush: 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 yellow trumpetbush, 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 yellow trumpetbush:
Apply a balanced slow-release fertiliser (e.g. 10-10-10) in early spring and again in midsummer. Container plants benefit from a liquid feed every 2–3 weeks during the active growing season. Avoid high-nitrogen feeds that promote foliage at the expense of flowers. 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 yellow trumpetbush 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 yellow trumpetbush
Half strength is the safe default for yellow trumpetbush — 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 yellow trumpetbush first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the yellow trumpetbush watering schedule.
Signs you are over-feeding yellow trumpetbush
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for yellow trumpetbush:
- 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 yellow trumpetbush
- 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 yellow trumpetbush care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of yellow trumpetbush 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 yellow trumpetbush
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 yellow trumpetbush — frequently asked questions
What fertiliser does yellow trumpetbush 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. Yellow Trumpetbush 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 yellow trumpetbush?
Apply a balanced slow-release fertiliser (e.g. 10-10-10) in early spring and again in midsummer. Container plants benefit from a liquid feed every 2–3 weeks during the active growing season. Avoid high-nitrogen feeds that promote foliage at the expense of flowers. Apply a balanced slow-release fertiliser (e.g. 10-10-10) in early spring and again in midsummer. Container plants benefit from a liquid feed every 2–3 weeks during the active growing season. Avoid high-nitrogen feeds that promote foliage at the expense of flowers. 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 yellow trumpetbush?
Half strength is the safe default for yellow trumpetbush — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding yellow trumpetbush 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 yellow trumpetbush 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 yellow trumpetbush?
Flush the pot of yellow trumpetbush 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
- Yellow Trumpetbush care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water yellow trumpetbush — 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 sonerila margaritacea
- How to fertilise sonerila heterostemon
- How to fertilise bertolonia maculata
- All 8452 fertilising guides in the Growli library