Fertilising guide

How to fertilise Burnet Saxifrage (Pimpinella saxifraga)— schedule & NPK

Also called Burnet Saxifrage, Lesser Burnet, Solidstem Burnet Saxifrage.

More about burnet saxifrage

About Burnet Saxifrage

Pimpinella saxifraga · also called Burnet Saxifrage, Lesser Burnet · herb

Pimpinella saxifraga is a slender, taproot-forming perennial herb in the carrot family (Apiaceae), native to dry grasslands, road verges, and chalk downland across the UK, Europe, and western Asia. It produces flat-topped umbels of tiny white flowers from June to September above a basal rosette of pinnate leaves, with smaller, finer stem leaves — a trait used to distinguish it from the similar greater burnet saxifrage (Pimpinella major). Leaves and seeds are edible with a mild anise-parsley flavour, and the root has a long history of medicinal use. Toxicity to cats and dogs is not confirmed by ASPCA; classified as mildly-toxic due to the presence of furanocoumarins in the Apiaceae family.

Growth habit: Upright, slender herbaceous perennial forming a basal rosette with branching stems bearing smaller, more finely divided leaves than the basal ones; dies back to the taproot in winter.

Watch for — Carrot fly (Psila rosae): As a member of the Apiaceae, burnet saxifrage is susceptible to carrot fly larvae tunnelling into the taproot; grow under fine insect mesh from May onwards or interplant with strong-scented herbs to deter adult flies.

What fertiliser burnet saxifrage actually wants — and why

Burnet Saxifrage 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 burnet saxifrage: 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 burnet saxifrage, 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 burnet saxifrage:

Feed sparingly if at all; a light top-dressing of well-composted material in early spring suffices on very poor soils — heavy feeding produces excess foliage and weakens the taproot. 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 burnet saxifrage 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 burnet saxifrage

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

Signs you are over-feeding burnet saxifrage

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

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 burnet saxifrage

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

Flushing and leaching the salts

Pot-grown burnet saxifrage 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 burnet saxifrage

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 burnet saxifrage — frequently asked questions

What fertiliser does burnet saxifrage 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. Burnet Saxifrage 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 burnet saxifrage?

Feed sparingly if at all; a light top-dressing of well-composted material in early spring suffices on very poor soils — heavy feeding produces excess foliage and weakens the taproot. Feed sparingly if at all; a light top-dressing of well-composted material in early spring suffices on very poor soils — heavy feeding produces excess foliage and weakens the taproot. 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 burnet saxifrage?