Fertilising guide
How to fertilise Crocosmia × crocosmiiflora 'Lucifer' (Crocosmia × crocosmiiflora 'Lucifer')— schedule & NPK
Also called Lucifer crocosmia, red crocosmia.
More about crocosmia × crocosmiiflora 'lucifer'
About Crocosmia × crocosmiiflora 'Lucifer'
Crocosmia × crocosmiiflora 'Lucifer' · also called Lucifer crocosmia, red crocosmia · flowering
Crocosmia 'Lucifer' is the boldest and hardiest montbretia, throwing arching sprays of intense flame-red flowers on tall stems above pleated sword-shaped foliage in mid to late summer. A vigorous corm-forming perennial holding the RHS Award of Garden Merit, it forms dramatic clumps in sun or light shade and is irresistible to hummingbirds and bees.
Growth habit: Vigorous clump-forming cormous perennial spreading by corms, with upright pleated sword-shaped leaves and tall, branching arched flower stems.
What fertiliser crocosmia × crocosmiiflora 'lucifer' actually wants — and why
Crocosmia × crocosmiiflora 'Lucifer' 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 crocosmia × crocosmiiflora 'lucifer': 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 crocosmia × crocosmiiflora 'lucifer', 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 crocosmia × crocosmiiflora 'lucifer':
Feed with a balanced general fertiliser in spring and again as flower stems form; a potash-rich feed supports flowering. Mulch with organic matter in spring to feed and conserve moisture. 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 crocosmia × crocosmiiflora 'lucifer' 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 crocosmia × crocosmiiflora 'lucifer'
Half strength is the safe default for crocosmia × crocosmiiflora 'lucifer' — 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 crocosmia × crocosmiiflora 'lucifer' first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the crocosmia × crocosmiiflora 'lucifer' watering schedule.
Signs you are over-feeding crocosmia × crocosmiiflora 'lucifer'
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for crocosmia × crocosmiiflora 'lucifer':
- 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 crocosmia × crocosmiiflora 'lucifer'
- 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 crocosmia × crocosmiiflora 'lucifer' care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of crocosmia × crocosmiiflora 'lucifer' 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 crocosmia × crocosmiiflora 'lucifer'
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 crocosmia × crocosmiiflora 'lucifer' — frequently asked questions
What fertiliser does crocosmia × crocosmiiflora 'lucifer' 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. Crocosmia × crocosmiiflora 'Lucifer' 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 crocosmia × crocosmiiflora 'lucifer'?
Feed with a balanced general fertiliser in spring and again as flower stems form; a potash-rich feed supports flowering. Mulch with organic matter in spring to feed and conserve moisture. Feed with a balanced general fertiliser in spring and again as flower stems form; a potash-rich feed supports flowering. Mulch with organic matter in spring to feed and conserve moisture. 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 crocosmia × crocosmiiflora 'lucifer'?
Half strength is the safe default for crocosmia × crocosmiiflora 'lucifer' — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding crocosmia × crocosmiiflora 'lucifer' 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 crocosmia × crocosmiiflora 'lucifer' 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 crocosmia × crocosmiiflora 'lucifer'?
Flush the pot of crocosmia × crocosmiiflora 'lucifer' 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
- Crocosmia × crocosmiiflora 'Lucifer' care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water crocosmia × crocosmiiflora 'lucifer' — 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 peace lily
- How to fertilise bird of paradise
- How to fertilise hoya
- All 5561 fertilising guides in the Growli library