Fertilising guide

How to fertilise Culantro (Eryngium foetidum)— schedule & NPK

Also called culantro, long coriander, sawtooth herb.

More about culantro

About Culantro

Eryngium foetidum · also called culantro, long coriander · herb

Culantro is a tropical biennial herb with long, serrated, strap-shaped leaves carrying a potent coriander-like flavour several times stronger than cilantro. A staple of Caribbean, Latin American, and Southeast Asian cooking, it forms a flat rosette and thrives in warm, humid, shaded conditions. Unlike cilantro it withstands heat and humidity without bolting quickly, making it the better choice in the tropics.

Growth habit: Low, flat, rosette-forming biennial of long, narrow, spiny-toothed leaves, sending up a branched flowering stalk of small bluish-green bristly flower heads in its second year or under stress.

What fertiliser culantro actually wants — and why

Culantro 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 culantro: 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 culantro, 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 culantro:

Feed every 3-4 weeks during active growth with a balanced or nitrogen-rich liquid fertiliser to sustain leafy rosette production, or mulch with compost. Steady feeding keeps leaves tender and delays bolting. 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 culantro 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 culantro

Half strength is a sensible default for culantro — 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 culantro first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the culantro watering schedule.

Signs you are over-feeding culantro

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for culantro:

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 culantro

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 culantro care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Pot-grown culantro 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 culantro

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 culantro — frequently asked questions

What fertiliser does culantro 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. Culantro 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 culantro?

Feed every 3-4 weeks during active growth with a balanced or nitrogen-rich liquid fertiliser to sustain leafy rosette production, or mulch with compost. Steady feeding keeps leaves tender and delays bolting. Feed every 3-4 weeks during active growth with a balanced or nitrogen-rich liquid fertiliser to sustain leafy rosette production, or mulch with compost. Steady feeding keeps leaves tender and delays bolting. 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 culantro?