Fertilising guide
How to fertilise Corkscrew Plant (Genlisea violacea)— schedule & NPK
Also called corkscrew plant, lobster pot plant.
More about corkscrew plant
About Corkscrew Plant
Genlisea violacea · also called corkscrew plant, lobster pot plant · houseplant
The corkscrew plant is an unusual Brazilian carnivore that traps tiny soil organisms underground with corkscrew-shaped 'lobster-pot' leaves, while showing only small green rosettes and violet flowers above the surface. It thrives boggy and warm, in waterlogged peat-sand, under bright light, watered only with mineral-free water. A curiosity for bog-terrarium growers.
Growth habit: Rootless rhizoid carnivore: small grass-like green rosettes sit on the surface while modified subterranean corkscrew (lobster-pot) leaves trap microfauna below; spreads slowly into a low clump.
What fertiliser corkscrew plant actually wants — and why
Corkscrew Plant 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 corkscrew plant: 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 corkscrew plant, 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 corkscrew plant:
No fertiliser. It captures protozoa and tiny invertebrates in its underground corkscrew traps, so it feeds itself from a healthy living medium. Adding nutrients to the soil or water damages it. 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 corkscrew plant 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 corkscrew plant
Half strength is the safe default for corkscrew plant — 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 corkscrew plant first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the corkscrew plant watering schedule.
Signs you are over-feeding corkscrew plant
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for corkscrew plant:
- 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 corkscrew plant
- 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 corkscrew plant care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of corkscrew plant 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 corkscrew plant
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 corkscrew plant — frequently asked questions
What fertiliser does corkscrew plant 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. Corkscrew Plant 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 corkscrew plant?
No fertiliser. It captures protozoa and tiny invertebrates in its underground corkscrew traps, so it feeds itself from a healthy living medium. Adding nutrients to the soil or water damages it. No fertiliser. It captures protozoa and tiny invertebrates in its underground corkscrew traps, so it feeds itself from a healthy living medium. Adding nutrients to the soil or water damages it. 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 corkscrew plant?
Half strength is the safe default for corkscrew plant — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding corkscrew plant 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 corkscrew plant 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 corkscrew plant?
Flush the pot of corkscrew plant 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
- Corkscrew Plant care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water corkscrew plant — 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 snake plant
- How to fertilise dracaena
- How to fertilise peperomia
- All 2464 fertilising guides in the Growli library