Fertilising guide
How to fertilise Weld (Reseda luteola)— schedule & NPK
Also called Weld, Dyer's Rocket, Wild Mignonette, Dyer's Weed.
More about weld
About Weld
Reseda luteola · also called Weld, Dyer's Rocket · herb
Reseda luteola is an erect biennial (occasionally annual) native to chalky, disturbed ground, roadsides, and quarry spoil across Europe and the Mediterranean, long cultivated as the most important yellow natural dye plant in European history; its stems and leaves yield luteolin and apigenin, producing fast, brilliant yellows on wool and silk. In the first year it forms a low, wavy-edged basal rosette; in its second year it bolts to a tall, unbranched spike packed with tiny yellowish-green flowers attractive to bees and hoverflies. It demands full sun, sharply drained alkaline soil, and minimal fertility to maintain its characteristic upright habit. Weld is not known to be toxic to cats or dogs.
Growth habit: Erect, largely unbranched biennial forming a basal rosette in year one, bolting to a tall flower and seed spike in year two.
Watch for — Stem lodging on fertile or sheltered sites: On enriched soil or in sheltered positions the tall flower spike becomes top-heavy and falls over; stake with a single cane if necessary or site in an open, breezy spot with poor soil.
What fertiliser weld actually wants — and why
Weld 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 weld: 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 weld, 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 weld:
No fertiliser required or recommended; high soil fertility is detrimental, promoting soft, leafy, low-dye-yield growth that is prone to wind damage. 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 weld 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 weld
Half strength is a sensible default for weld — 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 weld first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the weld watering schedule.
Signs you are over-feeding weld
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for weld:
- 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 weld
- 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 weld care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Pot-grown weld 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 weld
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 weld — frequently asked questions
What fertiliser does weld 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. Weld 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 weld?
No fertiliser required or recommended; high soil fertility is detrimental, promoting soft, leafy, low-dye-yield growth that is prone to wind damage. No fertiliser required or recommended; high soil fertility is detrimental, promoting soft, leafy, low-dye-yield growth that is prone to wind damage. 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 weld?
Half strength is a sensible default for weld — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.
What does over-feeding weld 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 weld 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 weld?
Pot-grown weld 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
- Weld care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water weld — 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 eastern bee balm
- How to fertilise white bergamot
- How to fertilise red bee balm
- All 10153 fertilising guides in the Growli library