Fertilising guide
How to fertilise Pine-scented Pelargonium (Pelargonium denticulatum)— schedule & NPK
Also called Pine-scented Pelargonium, Fernleaf Pelargonium, Toothed Pelargonium, Pine Geranium.
More about pine-scented pelargonium
About Pine-scented Pelargonium
Pelargonium denticulatum · also called Pine-scented Pelargonium, Fernleaf Pelargonium · herb
Pelargonium denticulatum is a finely cut-leaved, strongly aromatic species from South Africa's Western Cape, grown for its distinctively piny, balsamic-pine fragrance released on the slightest touch of the sticky, deeply toothed foliage. Upright in habit with small, pale to mid-pink flowers, it makes an excellent scented conservatory or patio container plant valued as much for olfactory interest as for ornament. It requires full sun, free-draining compost, and frost-free overwintering in all but the mildest UK and US gardens. Toxic to cats and dogs.
Growth habit: Upright to loosely spreading, semi-woody evergreen shrub with stiffly branched stems densely clothed in finely cut, sticky, strongly pine-scented leaves.
What fertiliser pine-scented pelargonium actually wants — and why
Pine-scented Pelargonium is a soft, fast leafy herb that you harvest hard — a modest balanced feed keeps tender growth coming without tipping it into bland or bolting.
A balanced general feed (even N-P-K) at modest strength — enough nitrogen to keep replacing the leaves you pick, but not so much that flavour thins or it bolts to seed.
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 pine-scented 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 pine-scented 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 pine-scented pelargonium:
Feed every 2 weeks during spring and summer with a balanced or high-potash liquid fertiliser; a high-nitrogen feed promotes soft, disease-prone growth at the expense of the aromatic oils. Stop feeding in autumn and winter. In practice: a balanced liquid feed every few weeks through the main growing and harvesting season (spring through early autumn), more often the harder you are picking it.
The dormant-season rule matters more than the exact interval: skip feeding entirely when pine-scented 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 pine-scented pelargonium
Half strength is a sensible default for pine-scented pelargonium — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.
Feeding always goes onto already-damp soil, never dry roots — water pine-scented pelargonium first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the pine-scented pelargonium watering schedule.
Signs you are over-feeding pine-scented pelargonium
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for pine-scented pelargonium:
- Fast, soft, pale growth with diluted, less aromatic flavour.
- Early bolting (running to flower) and a bitter edge.
- Salt crust and scorched tips on container plants.
Signs you are under-feeding pine-scented pelargonium
- Pale, slow regrowth after cutting and small leaves.
- A tired, stalled plant that cannot keep up with harvesting.
- Yellowing older leaves in a long-spent pot.
If the symptoms point at watering, light or roots rather than nutrition, the full pine-scented pelargonium care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Pot-grown pine-scented pelargonium builds up feed salts quickly — water until it drains each time and flush the pot with plain water every few weeks, especially on a sunny windowsill.
Organic vs synthetic feeds for pine-scented pelargonium
Organic options
A diluted seaweed feed or worm-casting tea keeps soft growth coming without overdoing it. UK: dilute seaweed or Westland; US: Espoma Garden-tone or Neptune's Harvest. Gentle, hard to overdo, flavour-friendly.
Synthetic / liquid feeds
A balanced liquid feed at half strength through harvesting — UK: Phostrogen, Baby Bio or Westland; US: Miracle-Gro all-purpose at half strength. Fast regrowth; just do not overdo the nitrogen.
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 pine-scented pelargonium — frequently asked questions
What fertiliser does pine-scented pelargonium need?
A balanced general feed (even N-P-K) at modest strength — enough nitrogen to keep replacing the leaves you pick, but not so much that flavour thins or it bolts to seed. Pine-scented Pelargonium is a soft, fast leafy herb that you harvest hard — a modest balanced feed keeps tender growth coming without tipping it into bland or bolting.
How often should I feed pine-scented pelargonium?
Feed every 2 weeks during spring and summer with a balanced or high-potash liquid fertiliser; a high-nitrogen feed promotes soft, disease-prone growth at the expense of the aromatic oils. Stop feeding in autumn and winter. Feed every 2 weeks during spring and summer with a balanced or high-potash liquid fertiliser; a high-nitrogen feed promotes soft, disease-prone growth at the expense of the aromatic oils. Stop feeding in autumn and winter. In practice: a balanced liquid feed every few weeks through the main growing and harvesting season (spring through early autumn), more often the harder you are picking it.
What strength of feed for pine-scented pelargonium?
Half strength is a sensible default for pine-scented pelargonium — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.
What does over-feeding pine-scented pelargonium look like?
Fast, soft, pale growth with diluted, less aromatic flavour. Early bolting (running to flower) and a bitter edge. Salt crust and scorched tips on container plants. Over-feeding pine-scented pelargonium with strong nitrogen is the usual mistake — it grows fast and lush but the leaves turn bland and it bolts to flower sooner, ending the useful harvest early.
Should I flush the soil of pine-scented pelargonium?
Pot-grown pine-scented pelargonium builds up feed salts quickly — water until it drains each time and flush the pot with plain water every few weeks, especially on a sunny windowsill.
Keep reading
- Pine-scented Pelargonium care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water pine-scented 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 etruscan santolina
- How to fertilise naples cotton lavender
- How to fertilise sardinian santolina
- All 10153 fertilising guides in the Growli library