Fertilising guide
How to fertilise Carrot-leaved Pelargonium (Pelargonium rapaceum)— schedule & NPK
Also called Carrot-leaved Pelargonium, Jakkalskos.
More about carrot-leaved pelargonium
About Carrot-leaved Pelargonium
Pelargonium rapaceum · also called Carrot-leaved Pelargonium, Jakkalskos · flowering
Pelargonium rapaceum is a tuberous geophyte from the Cape Floristic Region of South Africa, instantly recognisable by its soft, finely divided, carrot-like leaves arising from a large underground tuber. It produces clusters of yellow or creamy white flowers with dark nectar guides in spring, then enters complete summer dormancy. The critical care rule is to stop watering entirely when leaves die back in early summer, keeping the tuber bone dry until autumn regrowth begins. Toxic to cats, dogs, and horses.
Growth habit: Deciduous geophyte with a large, fleshy storage tuber; feathery, deeply dissected leaves appear in autumn, flowering occurs in late winter to spring, and the whole plant retreats underground each summer.
What fertiliser carrot-leaved pelargonium actually wants — and why
Carrot-leaved Pelargonium is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.
A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom.
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 carrot-leaved pelargonium: 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 carrot-leaved pelargonium, 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 carrot-leaved pelargonium:
Feed monthly with a low-nitrogen, high-potash liquid fertiliser during the growing season (autumn to spring); do not feed during summer dormancy. For a hungry bloomer that means feeding regularly — monthly — right through flowering across the main season (spring through early autumn), tapering as blooming ends.
The dormant-season rule matters more than the exact interval: skip feeding entirely when carrot-leaved pelargonium 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 carrot-leaved pelargonium
Follow the flowering-feed label rate for carrot-leaved pelargonium, or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.
Feeding always goes onto already-damp soil, never dry roots — water carrot-leaved pelargonium first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the carrot-leaved pelargonium watering schedule.
Signs you are over-feeding carrot-leaved pelargonium
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for carrot-leaved pelargonium:
- Lots of lush leaves but few flowers (too much nitrogen).
- Scorched leaf edges and salt crust from too-strong or too-frequent feeds.
- Soft, sappy growth prone to aphids and mildew.
Signs you are under-feeding carrot-leaved pelargonium
- Sparse, small, short-lived flowers and pale foliage.
- A tired plant that stops blooming early in the season.
- Weak growth and poor repeat-flowering after the first flush.
If the symptoms point at watering, light or roots rather than nutrition, the full carrot-leaved pelargonium care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Container-grown carrot-leaved pelargonium accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.
Organic vs synthetic feeds for carrot-leaved pelargonium
Organic options
A liquid comfrey or seaweed feed (naturally potassium-rich) plus compost or well-rotted manure as a mulch. UK: comfrey feed, organic Tomorite, or rose feed; US: Espoma Rose-tone or Neptune's Harvest. Feeds and improves soil.
Synthetic / liquid feeds
A high-potash flowering feed on a regular cadence — UK: Tomorite (Levington), Phostrogen or a specialist rose feed; US: Miracle-Gro Bloom Booster or a rose food. Fast, reliable bloom response.
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 carrot-leaved pelargonium — frequently asked questions
What fertiliser does carrot-leaved pelargonium need?
A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom. Carrot-leaved Pelargonium is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.
How often should I feed carrot-leaved pelargonium?
Feed monthly with a low-nitrogen, high-potash liquid fertiliser during the growing season (autumn to spring); do not feed during summer dormancy. Feed monthly with a low-nitrogen, high-potash liquid fertiliser during the growing season (autumn to spring); do not feed during summer dormancy. For a hungry bloomer that means feeding regularly — monthly — right through flowering across the main season (spring through early autumn), tapering as blooming ends.
What strength of feed for carrot-leaved pelargonium?
Follow the flowering-feed label rate for carrot-leaved pelargonium, or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.
What does over-feeding carrot-leaved pelargonium look like?
Lots of lush leaves but few flowers (too much nitrogen). Scorched leaf edges and salt crust from too-strong or too-frequent feeds. Soft, sappy growth prone to aphids and mildew. Using a high-nitrogen general feed on carrot-leaved pelargonium is the headline mistake — you grow a big leafy plant with few flowers. The second is simply under-feeding a genuinely hungry bloomer and getting a sparse, short display.
Should I flush the soil of carrot-leaved pelargonium?
Container-grown carrot-leaved pelargonium accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.
Keep reading
- Carrot-leaved Pelargonium care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water carrot-leaved pelargonium — 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 prairie dropseed
- How to fertilise giant sacaton grass
- How to fertilise muhly grass
- All 10153 fertilising guides in the Growli library