Fertilising guide
How to fertilise Lady of the Night (Brunfelsia americana)— schedule & NPK
Also called Lady of the Night, American Brunfelsia, Raintree.
More about lady of the night
About Lady of the Night
Brunfelsia americana · also called Lady of the Night, American Brunfelsia · tropical
Lady of the Night is a tropical shrub in the nightshade family, grown for its creamy-white to pale yellow tubular flowers that release an intoxicating vanilla-like fragrance exclusively after dusk. It blooms prolifically in warm climates in full sun to part shade. All parts are severely toxic to pets and humans. Hardy outdoors in USDA zones 9–11.
Growth habit: Upright, rounded, evergreen shrub; somewhat open habit that benefits from regular pruning
What fertiliser lady of the night actually wants — and why
Lady of the Night 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 lady of the night: 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 lady of the night, 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 lady of the night:
Apply a balanced slow-release fertiliser (e.g. 10-10-10) every 4–6 weeks through spring and summer. During active flowering, supplement with a liquid bloom formula (higher P and K) monthly. Brunfelsia benefits from slightly acidifying fertilisers such as those formulated for camellias or azaleas, which also supply micronutrients suited to its acid-soil preference. Treat that as monthly 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 lady of the night 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 lady of the night
Half strength is the safe default for lady of the night — 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 lady of the night first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the lady of the night watering schedule.
Signs you are over-feeding lady of the night
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for lady of the night:
- 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 lady of the night
- 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 lady of the night care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of lady of the night 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 lady of the night
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 lady of the night — frequently asked questions
What fertiliser does lady of the night 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. Lady of the Night 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 lady of the night?
Apply a balanced slow-release fertiliser (e.g. 10-10-10) every 4–6 weeks through spring and summer. During active flowering, supplement with a liquid bloom formula (higher P and K) monthly. Brunfelsia benefits from slightly acidifying fertilisers such as those formulated for camellias or azaleas, which also supply micronutrients suited to its acid-soil preference. Apply a balanced slow-release fertiliser (e.g. 10-10-10) every 4–6 weeks through spring and summer. During active flowering, supplement with a liquid bloom formula (higher P and K) monthly. Brunfelsia benefits from slightly acidifying fertilisers such as those formulated for camellias or azaleas, which also supply micronutrients suited to its acid-soil preference. Treat that as monthly 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 lady of the night?
Half strength is the safe default for lady of the night — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding lady of the night 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 lady of the night 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 lady of the night?
Flush the pot of lady of the night 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
- Lady of the Night care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water lady of the night — 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 day-blooming jasmine
- How to fertilise crimson cestrum
- How to fertilise chiric sanango
- All 6887 fertilising guides in the Growli library