Fertilising guide
How to fertilise Southernwood-leaved Pelargonium (Pelargonium abrotanifolium)— schedule & NPK
Also called Southernwood-leaved Pelargonium, Camphor Pelargonium, Wormwood-leaved Geranium.
More about southernwood-leaved pelargonium
About Southernwood-leaved Pelargonium
Pelargonium abrotanifolium · also called Southernwood-leaved Pelargonium, Camphor Pelargonium · herb
Pelargonium abrotanifolium is a compact, shrubby scented-leaf species from the dry rocky hillsides of South Africa's Western and Eastern Cape, named for its feathery, deeply divided leaves that closely resemble those of southernwood (Artemisia abrotanum) and carry a fresh, camphor-like fragrance. Small white to pale pink flowers with dark-purple veining appear through spring and summer. Hardy to a light frost once established but best treated as a conservatory or frost-free patio plant in the UK; it is one of the more drought-tolerant pelargoniums and must have sharply draining soil. Toxic to cats and dogs.
Growth habit: Compact, bushy, semi-woody evergreen shrublet with finely divided, feathery, camphor-scented foliage; naturally well-branched with a twiggy, mounded habit.
What fertiliser southernwood-leaved pelargonium actually wants — and why
Southernwood-leaved 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 southernwood-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 southernwood-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 southernwood-leaved pelargonium:
Feed monthly with a high-potash liquid fertiliser during spring and summer; this lean-growing species does not need heavy feeding and excess nitrogen promotes soft, weakly fragrant growth. Cease feeding from autumn until new spring growth begins. 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 southernwood-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 southernwood-leaved pelargonium
Half strength is a sensible default for southernwood-leaved 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 southernwood-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 southernwood-leaved pelargonium watering schedule.
Signs you are over-feeding southernwood-leaved pelargonium
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for southernwood-leaved 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 southernwood-leaved 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 southernwood-leaved pelargonium care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Pot-grown southernwood-leaved 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 southernwood-leaved 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 southernwood-leaved pelargonium — frequently asked questions
What fertiliser does southernwood-leaved 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. Southernwood-leaved 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 southernwood-leaved pelargonium?
Feed monthly with a high-potash liquid fertiliser during spring and summer; this lean-growing species does not need heavy feeding and excess nitrogen promotes soft, weakly fragrant growth. Cease feeding from autumn until new spring growth begins. Feed monthly with a high-potash liquid fertiliser during spring and summer; this lean-growing species does not need heavy feeding and excess nitrogen promotes soft, weakly fragrant growth. Cease feeding from autumn until new spring growth begins. 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 southernwood-leaved pelargonium?
Half strength is a sensible default for southernwood-leaved pelargonium — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.
What does over-feeding southernwood-leaved 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 southernwood-leaved 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 southernwood-leaved pelargonium?
Pot-grown southernwood-leaved 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
- Southernwood-leaved Pelargonium care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water southernwood-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 milk thistle
- How to fertilise elder
- How to fertilise st. john's wort
- All 10153 fertilising guides in the Growli library