Fertilising guide

How to fertilise Korean Angelica (Angelica gigas)— schedule & NPK

Also called Korean Angelica, Giant Purple Angelica, Korean Masterwort.

More about korean angelica

About Korean Angelica

Angelica gigas · also called Korean Angelica, Giant Purple Angelica · flowering

Korean Angelica is a dramatic biennial or short-lived perennial prized for its deep burgundy-purple umbel flowers and bold, architectural foliage. It thrives in moist, humus-rich soil with partial shade and cool conditions. Plants self-seed freely, making them naturalise well in woodland gardens and damp borders.

Growth habit: Upright, clump-forming biennial or monocarpic perennial; rosette of large pinnate leaves in year one, tall flowering stems in year two

What fertiliser korean angelica actually wants — and why

Korean Angelica flowers best on poor soil — feed it and you get a lush leafy plant with very few blooms, the exact opposite of what you want.

Little or nothing. Rich, especially nitrogen-rich, soil pushes foliage at the expense of flowers in this plant — lean ground is the technique, not a deficiency.

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 korean angelica: 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 korean angelica, 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 korean angelica:

Apply a balanced slow-release fertiliser (10-10-10) in early spring. A further liquid feed of potassium-rich fertiliser when flower buds form encourages strong bloom. Avoid excess nitrogen, which promotes leafy growth at the expense of flowers. In practice: no routine feeding at all for korean angelica — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

The dormant-season rule matters more than the exact interval: skip feeding entirely when korean angelica 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 korean angelica

None is the correct answer for korean angelica. The flower-versus-foliage trade-off is the whole point: hold back and you get the display.

Feeding always goes onto already-damp soil, never dry roots — water korean angelica first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the korean angelica watering schedule.

Signs you are over-feeding korean angelica

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

Abundant leafy growth and very few flowers (the classic over-rich symptom).
Soft, floppy stems and a sprawling, leafy habit.
Scorched edges and salt crust if it has been fed in a container.

Signs you are under-feeding korean angelica

Effectively never an issue — these plants flower on poverty.
Only on genuinely dead soil: weak, thin growth and few blooms.
A short-lived plant in completely spent container compost.

If the symptoms point at watering, light or roots rather than nutrition, the full korean angelica care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

If korean angelica has accidentally been fed and is all leaf, a plain-water flush plus a move to leaner soil resets it; otherwise no flushing is needed because you are not feeding it.

Organic vs synthetic feeds for korean angelica

Organic options

A thin compost mulch for soil structure is the absolute most; mostly, give it nothing. UK/US: leave it lean — no manure, no liquid feed. Poor soil is the active ingredient here.

Synthetic / liquid feeds

None. Synthetic feeds, particularly anything with appreciable nitrogen, directly suppress flowering in korean angelica.

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 korean angelica — frequently asked questions

What fertiliser does korean angelica need?

Little or nothing. Rich, especially nitrogen-rich, soil pushes foliage at the expense of flowers in this plant — lean ground is the technique, not a deficiency. Korean Angelica flowers best on poor soil — feed it and you get a lush leafy plant with very few blooms, the exact opposite of what you want.

How often should I feed korean angelica?

Apply a balanced slow-release fertiliser (10-10-10) in early spring. A further liquid feed of potassium-rich fertiliser when flower buds form encourages strong bloom. Avoid excess nitrogen, which promotes leafy growth at the expense of flowers. Apply a balanced slow-release fertiliser (10-10-10) in early spring. A further liquid feed of potassium-rich fertiliser when flower buds form encourages strong bloom. Avoid excess nitrogen, which promotes leafy growth at the expense of flowers. In practice: no routine feeding at all for korean angelica — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

What strength of feed for korean angelica?