Fertilising guide
How to fertilise Selfheal (Prunella vulgaris)— schedule & NPK
Also called Selfheal, Common Selfheal, Heal-All, All-Heal.
More about selfheal
About Selfheal
Prunella vulgaris · also called Selfheal, Common Selfheal · herb
Prunella vulgaris is a low-growing, creeping perennial herb native throughout Europe, Asia, and North America, commonly found in lawns, meadows, roadsides, and open woodland. It produces dense, squarish spikes of purple, two-lipped flowers from June to October and has been used in herbal medicine for centuries as an antiseptic and wound-healing herb, particularly in Traditional Chinese Medicine. It tolerates a wide range of soils and light conditions but performs best in moist, reasonably fertile soil with some sun. Selfheal is not known to be toxic to cats or dogs.
Growth habit: Low, creeping to semi-erect perennial that roots at nodes; spreads to form dense mats in lawns and borders.
What fertiliser selfheal actually wants — and why
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 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 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 selfheal:
No routine feeding required in garden settings; a light application of balanced fertiliser in spring can increase flower spike production if the plant is grown as a medicinal herb crop. 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 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 selfheal
Half strength is a sensible default for 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 selfheal first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the selfheal watering schedule.
Signs you are over-feeding selfheal
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for 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 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 selfheal care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Pot-grown 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 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 selfheal — frequently asked questions
What fertiliser does 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. 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 selfheal?
No routine feeding required in garden settings; a light application of balanced fertiliser in spring can increase flower spike production if the plant is grown as a medicinal herb crop. No routine feeding required in garden settings; a light application of balanced fertiliser in spring can increase flower spike production if the plant is grown as a medicinal herb crop. 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 selfheal?
Half strength is a sensible default for selfheal — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.
What does over-feeding selfheal 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 selfheal 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 selfheal?
Pot-grown 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.
Keep reading
- Selfheal care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water selfheal — 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 french sorrel
- How to fertilise red-veined sorrel
- How to fertilise golden lemon balm
- All 10153 fertilising guides in the Growli library