Fertilising guide
How to fertilise Hybrid trumpet vine (Campsis x tagliabuana)— schedule & NPK
Also called Hybrid trumpet vine, Trumpet creeper, Madame Galen trumpet vine.
More about hybrid trumpet vine
About Hybrid trumpet vine
Campsis x tagliabuana · also called Hybrid trumpet vine, Trumpet creeper · flowering
Hybrid trumpet vine (Campsis radicans × C. grandiflora) is a powerful, woody, deciduous climber bearing large salmon-red to orange trumpet flowers beloved by hummingbirds throughout summer and into autumn. Hardy in USDA zones 4–9, it needs a warm, sunny wall and annual pruning to stay manageable. All parts may cause mild skin irritation.
Growth habit: Vigorous woody deciduous climber, self-clinging with aerial rootlets
What fertiliser hybrid trumpet vine actually wants — and why
Hybrid trumpet vine 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 hybrid trumpet vine: 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 hybrid trumpet vine, 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 hybrid trumpet vine:
Apply a balanced slow-release fertiliser in early spring. In very fertile soils, no feeding is needed. Excess nitrogen promotes rampant leafy growth and suppresses flowering. A potassium-high feed in late spring can boost flower production. 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 hybrid trumpet vine 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 hybrid trumpet vine
Half strength is the safe default for hybrid trumpet vine — 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 hybrid trumpet vine first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the hybrid trumpet vine watering schedule.
Signs you are over-feeding hybrid trumpet vine
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for hybrid trumpet vine:
- 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 hybrid trumpet vine
- 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 hybrid trumpet vine care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of hybrid trumpet vine 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 hybrid trumpet vine
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 hybrid trumpet vine — frequently asked questions
What fertiliser does hybrid trumpet vine 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. Hybrid trumpet vine 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 hybrid trumpet vine?
Apply a balanced slow-release fertiliser in early spring. In very fertile soils, no feeding is needed. Excess nitrogen promotes rampant leafy growth and suppresses flowering. A potassium-high feed in late spring can boost flower production. Apply a balanced slow-release fertiliser in early spring. In very fertile soils, no feeding is needed. Excess nitrogen promotes rampant leafy growth and suppresses flowering. A potassium-high feed in late spring can boost flower production. 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 hybrid trumpet vine?
Half strength is the safe default for hybrid trumpet vine — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding hybrid trumpet vine 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 hybrid trumpet vine 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 hybrid trumpet vine?
Flush the pot of hybrid trumpet vine 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
- Hybrid trumpet vine care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water hybrid trumpet vine — 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 dwarf astilbe 'pumila'
- How to fertilise bedding begonia
- How to fertilise annual phlox 'sugar stars'
- All 6887 fertilising guides in the Growli library