Fertilising guide

How to fertilise Valerian (Valeriana officinalis)— schedule & NPK

Also called valerian, garden valerian, all-heal.

More about valerian

About Valerian

Valeriana officinalis · also called valerian, garden valerian · herb

Valerian is a tall, clump-forming perennial grown for its sweetly scented clusters of pale pink-white flowers and its sedative-reputed root, used medicinally for centuries. It bears fern-like divided leaves and airy flower heads that draw pollinators, thriving in moist, fertile soil and sun to part shade. Hardy and easy, it self-seeds freely and naturalises in damp meadows and stream banks.

Growth habit: Upright, clump-forming herbaceous perennial with deeply divided pinnate leaves and tall hollow stems topped by domed clusters of fragrant tiny pink-white flowers in early summer.

What fertiliser valerian actually wants — and why

Valerian 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 valerian: 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 valerian, 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 valerian:

Undemanding. A spring mulch of compost or one application of balanced general fertiliser is sufficient; avoid heavy feeding, which produces tall floppy stems at the expense of root quality. 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 valerian 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 valerian

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

Signs you are over-feeding valerian

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

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 valerian

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

Flushing and leaching the salts

Pot-grown valerian 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 valerian

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 valerian — frequently asked questions

What fertiliser does valerian 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. Valerian 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 valerian?

Undemanding. A spring mulch of compost or one application of balanced general fertiliser is sufficient; avoid heavy feeding, which produces tall floppy stems at the expense of root quality. Undemanding. A spring mulch of compost or one application of balanced general fertiliser is sufficient; avoid heavy feeding, which produces tall floppy stems at the expense of root quality. 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 valerian?