Fertilising guide
How to fertilise Long-tongue Tongue Plant (Glottiphyllum longum)— schedule & NPK
Also called Tongue Plant, Tongue Leaf.
More about long-tongue tongue plant
About Long-tongue Tongue Plant
Glottiphyllum longum · also called Tongue Plant, Tongue Leaf · houseplant
Glottiphyllum longum is a compact South African succulent in the Aizoaceae family, prized for its elongated, tongue-shaped, bright-green leaves and vivid yellow daisy-like flowers. It thrives with very infrequent watering, intense sun, and near-dry soil. Not confirmed non-toxic by ASPCA; keep away from pets as a precaution.
Growth habit: Low-growing, clump-forming succulent rosette
Watch for — Etiolation (stretching): Pale, elongated leaves indicate insufficient light. Move to a brighter spot with direct sun.
What fertiliser long-tongue tongue plant actually wants — and why
Long-tongue Tongue 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 long-tongue tongue 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 long-tongue tongue 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 long-tongue tongue plant:
Feed once in spring and once in early summer with a dilute, low-nitrogen cactus or succulent fertiliser at half the recommended strength. Do not feed in autumn or winter. 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 long-tongue tongue 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 long-tongue tongue plant
Half strength is the safe default for long-tongue tongue 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 long-tongue tongue plant first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the long-tongue tongue plant watering schedule.
Signs you are over-feeding long-tongue tongue plant
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for long-tongue tongue 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 long-tongue tongue 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 long-tongue tongue plant care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of long-tongue tongue 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 long-tongue tongue 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 long-tongue tongue plant — frequently asked questions
What fertiliser does long-tongue tongue 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. Long-tongue Tongue 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 long-tongue tongue plant?
Feed once in spring and once in early summer with a dilute, low-nitrogen cactus or succulent fertiliser at half the recommended strength. Do not feed in autumn or winter. Feed once in spring and once in early summer with a dilute, low-nitrogen cactus or succulent fertiliser at half the recommended strength. Do not feed in autumn or winter. 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 long-tongue tongue plant?
Half strength is the safe default for long-tongue tongue plant — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding long-tongue tongue 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 long-tongue tongue 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 long-tongue tongue plant?
Flush the pot of long-tongue tongue 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
- Long-tongue Tongue Plant care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water long-tongue tongue plant — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
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- All 11687 fertilising guides in the Growli library