Fertilising guide
How to fertilise Large-Bulb Bulbophyllum (Bulbophyllum macrobulbon)— schedule & NPK
Also called Large-Bulb Bulbophyllum, Large Bulbed Bulbophyllum.
More about large-bulb bulbophyllum
About Large-Bulb Bulbophyllum
Bulbophyllum macrobulbon · also called Large-Bulb Bulbophyllum, Large Bulbed Bulbophyllum · tropical
Bulbophyllum macrobulbon is an imposing hot-growing epiphyte endemic to New Guinea, producing some of the largest pseudobulbs in the genus — 5–8 cm ovoid, each bearing a single fleshy leaf to 60 cm long often tinged purple. Flowers are large, foul-smelling, and waxy. It requires consistently warm temperatures, high humidity, and bright filtered light, with many years needed before first flowering.
Growth habit: Large creeping sympodial epiphyte with prominently spaced, oversized ovoid pseudobulbs along a thick rhizome; single pendulous leaf per pseudobulb; requires considerable horizontal space
Watch for — Leaf tip browning: Brown leaf tips are usually caused by low humidity, fluoride in tap water, or salt build-up in the growing medium. Raise humidity above 60%, switch to rainwater, and flush the medium monthly with plain water to clear accumulated mineral salts.
What fertiliser large-bulb bulbophyllum actually wants — and why
Large-Bulb Bulbophyllum 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 large-bulb bulbophyllum: 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 large-bulb bulbophyllum, 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 large-bulb bulbophyllum:
Apply a balanced orchid fertiliser fortnightly at half strength during spring and summer. Reduce to monthly in autumn and winter. A potassium-rich formula in late summer can help encourage flowering in mature plants. Flush the medium with plain water monthly. 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 large-bulb bulbophyllum 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 large-bulb bulbophyllum
Half strength is the safe default for large-bulb bulbophyllum — 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 large-bulb bulbophyllum first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the large-bulb bulbophyllum watering schedule.
Signs you are over-feeding large-bulb bulbophyllum
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for large-bulb bulbophyllum:
- 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 large-bulb bulbophyllum
- 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 large-bulb bulbophyllum care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of large-bulb bulbophyllum 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 large-bulb bulbophyllum
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 large-bulb bulbophyllum — frequently asked questions
What fertiliser does large-bulb bulbophyllum 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. Large-Bulb Bulbophyllum 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 large-bulb bulbophyllum?
Apply a balanced orchid fertiliser fortnightly at half strength during spring and summer. Reduce to monthly in autumn and winter. A potassium-rich formula in late summer can help encourage flowering in mature plants. Flush the medium with plain water monthly. Apply a balanced orchid fertiliser fortnightly at half strength during spring and summer. Reduce to monthly in autumn and winter. A potassium-rich formula in late summer can help encourage flowering in mature plants. Flush the medium with plain water monthly. 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 large-bulb bulbophyllum?
Half strength is the safe default for large-bulb bulbophyllum — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding large-bulb bulbophyllum 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 large-bulb bulbophyllum 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 large-bulb bulbophyllum?
Flush the pot of large-bulb bulbophyllum 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
- Large-Bulb Bulbophyllum care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water large-bulb bulbophyllum — 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 wild garlic vine
- How to fertilise monkey comb vine
- How to fertilise garlic bignone
- All 8452 fertilising guides in the Growli library