Fertilising guide
How to fertilise African Wormwood (Artemisia afra)— schedule & NPK
Also called African Wormwood, African Wilde Als, Lengana.
More about african wormwood
About African Wormwood
Artemisia afra · also called African Wormwood, African Wilde Als · herb
African Wormwood is a fast-growing, aromatic shrubby perennial native to southern and eastern Africa, widely used in traditional medicine (umuthi/lengana). It produces finely divided, feathery grey-green foliage with a distinctive camphor-like fragrance. Hardy in warm-temperate climates; tolerates light frost. Requires full sun and sharply drained soil.
Growth habit: Upright, bushy shrubby perennial; woody at the base
What fertiliser african wormwood actually wants — and why
African Wormwood is a lean, aromatic herb — the essential-oil flavour you grow it for is strongest in poor soil, so feeding it actively makes it worse.
Little or nothing. If anything, a very weak balanced feed or a thin compost top-dress — never a rich nitrogen feed, which dilutes the aromatic oils and produces soft, bland, floppy growth.
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 african wormwood: 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 african wormwood, 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 african wormwood:
Light feeder. Apply a balanced slow-release fertiliser once in spring. Over-fertilising, especially with nitrogen-rich feeds, produces soft, disease-prone growth and reduces essential oil concentration in the foliage. In practice: a spring compost top-dress at most, and otherwise leave african wormwood unfed — lean, sharp-draining soil is exactly what concentrates its flavour.
The dormant-season rule matters more than the exact interval: skip feeding entirely when african wormwood 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 african wormwood
As weak as it gets for african wormwood, or none at all. The flavour-versus-growth trade-off runs the opposite way to leafy crops: restraint is the technique.
Feeding always goes onto already-damp soil, never dry roots — water african wormwood first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the african wormwood watering schedule.
Signs you are over-feeding african wormwood
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for african wormwood:
- Lush, soft, fast growth with noticeably weaker scent and flavour.
- Floppy stems, sparse essential oils, and poor cold/wet hardiness.
- Salt crust in containers and scorched leaf tips from over-feeding.
Signs you are under-feeding african wormwood
- Rare — these herbs thrive on lean soil.
- Only on truly exhausted soil: pale, thin, very slow growth.
- A short-lived, weak plant in a long-spent container.
If the symptoms point at watering, light or roots rather than nutrition, the full african wormwood care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Over-feeding is so unlikely with african wormwood that flushing is rarely needed; if a container has had feed, a single plain-water flush and a switch to a leaner, grittier mix resets it.
Organic vs synthetic feeds for african wormwood
Organic options
A thin spring mulch of garden compost or leaf-mould is the most these want. UK: a little garden compost; US: a light Espoma Garden-tone top-dress at most. Lean and gritty beats fed and rich every time.
Synthetic / liquid feeds
Generally none for african wormwood. At absolute most, a very dilute balanced feed once or twice in a container; in the ground, nothing — synthetic feeds work directly against the flavour.
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 african wormwood — frequently asked questions
What fertiliser does african wormwood need?
Little or nothing. If anything, a very weak balanced feed or a thin compost top-dress — never a rich nitrogen feed, which dilutes the aromatic oils and produces soft, bland, floppy growth. African Wormwood is a lean, aromatic herb — the essential-oil flavour you grow it for is strongest in poor soil, so feeding it actively makes it worse.
How often should I feed african wormwood?
Light feeder. Apply a balanced slow-release fertiliser once in spring. Over-fertilising, especially with nitrogen-rich feeds, produces soft, disease-prone growth and reduces essential oil concentration in the foliage. Light feeder. Apply a balanced slow-release fertiliser once in spring. Over-fertilising, especially with nitrogen-rich feeds, produces soft, disease-prone growth and reduces essential oil concentration in the foliage. In practice: a spring compost top-dress at most, and otherwise leave african wormwood unfed — lean, sharp-draining soil is exactly what concentrates its flavour.
What strength of feed for african wormwood?
As weak as it gets for african wormwood, or none at all. The flavour-versus-growth trade-off runs the opposite way to leafy crops: restraint is the technique.
What does over-feeding african wormwood look like?
Lush, soft, fast growth with noticeably weaker scent and flavour. Floppy stems, sparse essential oils, and poor cold/wet hardiness. Salt crust in containers and scorched leaf tips from over-feeding. Feeding african wormwood like a leafy vegetable is the defining mistake — rich nitrogen gives you a big, soft, fast plant whose leaves are watery and bland, with weak winter-rot resistance.
Should I flush the soil of african wormwood?
Over-feeding is so unlikely with african wormwood that flushing is rarely needed; if a container has had feed, a single plain-water flush and a switch to a leaner, grittier mix resets it.
Keep reading
- African Wormwood care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water african wormwood — 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 tasmanian blue gum
- How to fertilise ashwagandha
- How to fertilise tulsi kapoor
- All 8452 fertilising guides in the Growli library