Fertilising guide
How to fertilise Leaf Celery (Apium graveolens var. secalinum)— schedule & NPK
Also called Leaf Celery, Chinese Celery, Cutting Celery, Smallage.
More about leaf celery
About Leaf Celery
Apium graveolens var. secalinum · also called Leaf Celery, Chinese Celery · herb
Leaf Celery is a heritage variety of celery grown primarily for its abundant, intensely flavoured leaves rather than thick stalks. Far more tolerant of heat, cold, and neglect than stalk celery, it is treated like a cut-and-come-again herb. The leaves have a concentrated celery flavour ideal for soups, stocks, and Asian cooking.
Growth habit: Upright, clumping biennial grown as an annual or short-lived perennial; produces prolific foliage from a central crown
What fertiliser leaf celery actually wants — and why
Leaf Celery 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 leaf celery: 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 leaf celery, 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 leaf celery:
Apply a balanced nitrogen-rich liquid fertiliser (e.g. 10-5-5 or a general-purpose liquid feed) every 2–3 weeks during the growing season to support the rapid production of leafy growth. A slow-release granular fertiliser incorporated at planting time reduces the need for frequent liquid feeding. 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 leaf celery 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 leaf celery
Half strength is a sensible default for leaf celery — 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 leaf celery first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the leaf celery watering schedule.
Signs you are over-feeding leaf celery
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for leaf celery:
- 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 leaf celery
- 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 leaf celery care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Pot-grown leaf celery 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 leaf celery
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 leaf celery — frequently asked questions
What fertiliser does leaf celery 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. Leaf Celery 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 leaf celery?
Apply a balanced nitrogen-rich liquid fertiliser (e.g. 10-5-5 or a general-purpose liquid feed) every 2–3 weeks during the growing season to support the rapid production of leafy growth. A slow-release granular fertiliser incorporated at planting time reduces the need for frequent liquid feeding. Apply a balanced nitrogen-rich liquid fertiliser (e.g. 10-5-5 or a general-purpose liquid feed) every 2–3 weeks during the growing season to support the rapid production of leafy growth. A slow-release granular fertiliser incorporated at planting time reduces the need for frequent liquid feeding. 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 leaf celery?
Half strength is a sensible default for leaf celery — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.
What does over-feeding leaf celery 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 leaf celery 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 leaf celery?
Pot-grown leaf celery 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
- Leaf Celery care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water leaf celery — 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 syrian oregano
- How to fertilise dittany of crete
- How to fertilise barbecue rosemary
- All 6887 fertilising guides in the Growli library