Fertilising guide

How to fertilise Cut-leaved Selfheal (Prunella laciniata)— schedule & NPK

Also called Cut-leaved Selfheal, Cutleaf Self-Heal, White Selfheal.

More about cut-leaved selfheal

About Cut-leaved Selfheal

Prunella laciniata · also called Cut-leaved Selfheal, Cutleaf Self-Heal · herb

Prunella laciniata is a semi-evergreen, mat-forming perennial native to dry, sunny grassland and calcareous soils across central and southern Europe, occurring as a scarce native or naturalised plant in parts of the UK. It closely resembles the common selfheal (P. vulgaris) but is distinguished by its deeply lobed, pinnatifid leaves and creamy-white flowers borne on short, dense spikes. Unlike P. vulgaris it demands sharply drained, low-fertility soil in full sun and sulks in heavy clay or high-nutrient borders. It is not known to be toxic to cats or dogs.

Growth habit: Prostrate to semi-erect, creeping perennial with rooting nodes; forms a low mat spreading to 30–40 cm.

What fertiliser cut-leaved selfheal actually wants — and why

Cut-leaved Selfheal 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 cut-leaved selfheal: 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 cut-leaved selfheal, 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 cut-leaved selfheal:

Little or no fertiliser needed; an annual top-dressing of grit or fine gravel maintains drainage and low fertility without encouraging coarse growth. 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 cut-leaved selfheal 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 cut-leaved selfheal

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

Signs you are over-feeding cut-leaved selfheal

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

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 cut-leaved selfheal

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 cut-leaved selfheal care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Pot-grown cut-leaved selfheal 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 cut-leaved selfheal

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 cut-leaved selfheal — frequently asked questions

What fertiliser does cut-leaved selfheal 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. Cut-leaved Selfheal 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 cut-leaved selfheal?

Little or no fertiliser needed; an annual top-dressing of grit or fine gravel maintains drainage and low fertility without encouraging coarse growth. Little or no fertiliser needed; an annual top-dressing of grit or fine gravel maintains drainage and low fertility without encouraging coarse growth. 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 cut-leaved selfheal?