Fertilising guide
How to fertilise Common immortelle (Xeranthemum annuum)— schedule & NPK
Also called Common immortelle, Annual everlasting, Immortelle.
More about common immortelle
About Common immortelle
Xeranthemum annuum · also called Common immortelle, Annual everlasting · flowering
A drought-tolerant annual everlasting from southern Europe and western Asia, growing 30–60 cm with silvery-grey woolly stems and papery daisy-like heads in white, pink, lilac, or crimson. Blooms all summer. Exceptionally easy to grow in full sun and poor, well-drained soil; ideal for dried flower arrangements.
Growth habit: Erect, slender-stemmed annual; branching with woolly grey-green foliage
What fertiliser common immortelle actually wants — and why
Common immortelle 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 common immortelle: 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 common immortelle, 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 common immortelle:
One light feed of balanced granular fertiliser at planting time is sufficient. Over-fertilising, especially with nitrogen, reduces flowering. On naturally poor or sandy soils, a single balanced liquid feed in early summer can be beneficial. 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 common immortelle 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 common immortelle
Half strength is the safe default for common immortelle — 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 common immortelle first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the common immortelle watering schedule.
Signs you are over-feeding common immortelle
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for common immortelle:
- 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 common immortelle
- 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 common immortelle care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of common immortelle 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 common immortelle
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 common immortelle — frequently asked questions
What fertiliser does common immortelle 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. Common immortelle 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 common immortelle?
One light feed of balanced granular fertiliser at planting time is sufficient. Over-fertilising, especially with nitrogen, reduces flowering. On naturally poor or sandy soils, a single balanced liquid feed in early summer can be beneficial. One light feed of balanced granular fertiliser at planting time is sufficient. Over-fertilising, especially with nitrogen, reduces flowering. On naturally poor or sandy soils, a single balanced liquid feed in early summer can be beneficial. 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 common immortelle?
Half strength is the safe default for common immortelle — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding common immortelle 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 common immortelle 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 common immortelle?
Flush the pot of common immortelle 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
- Common immortelle care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water common immortelle — 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 8452 fertilising guides in the Growli library