Fertilising guide
How to fertilise Large Cattleya (Cattleya maxima)— schedule & NPK
Also called Large Cattleya, Maxima Orchid.
More about large cattleya
About Large Cattleya
Cattleya maxima · also called Large Cattleya, Maxima Orchid · tropical
Cattleya maxima is a unifoliate cattleya native to Ecuador, Peru, and Colombia, revered for producing some of the largest flower clusters in the genus — up to 15 blooms per stem. The pale lavender to rose-lilac flowers feature a distinctive lip with dark purple veining. It blooms in autumn to early winter and grows vigorously in intermediate to warm conditions with high light.
Growth habit: Robust unifoliate sympodial epiphyte with stout, club-shaped pseudobulbs and single broad, leathery leaves. Produces the largest flower clusters in the genus — 10–15 blooms per stem — on an erect inflorescence from a terminal sheath.
What fertiliser large cattleya actually wants — and why
Large Cattleya 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 cattleya: 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 cattleya, 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 cattleya:
Feed every 2 weeks at half-strength with a balanced orchid fertiliser (20-20-20) during spring and summer growth. Transition to a bloom-booster (10-30-20) from late summer to support autumn flower development. During the winter rest, reduce to monthly feeding at quarter-strength. 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 large cattleya 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 cattleya
Half strength is the safe default for large cattleya — 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 cattleya first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the large cattleya watering schedule.
Signs you are over-feeding large cattleya
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for large cattleya:
- 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 cattleya
- 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 cattleya care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of large cattleya 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 cattleya
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 cattleya — frequently asked questions
What fertiliser does large cattleya 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 Cattleya 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 cattleya?
Feed every 2 weeks at half-strength with a balanced orchid fertiliser (20-20-20) during spring and summer growth. Transition to a bloom-booster (10-30-20) from late summer to support autumn flower development. During the winter rest, reduce to monthly feeding at quarter-strength. Feed every 2 weeks at half-strength with a balanced orchid fertiliser (20-20-20) during spring and summer growth. Transition to a bloom-booster (10-30-20) from late summer to support autumn flower development. During the winter rest, reduce to monthly feeding at quarter-strength. 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 large cattleya?
Half strength is the safe default for large cattleya — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding large cattleya 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 cattleya 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 cattleya?
Flush the pot of large cattleya 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 Cattleya care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water large cattleya — 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 küster's ceratozamia
- How to fertilise zaragoza ceratozamia
- How to fertilise miranda's ceratozamia
- All 6887 fertilising guides in the Growli library