Small pile of dark brown Japanese indigo seeds on a textured beige surface
Group of people standing in a field with persicaria plants and grey sky
Single Persicaria tinctoria seed on a light grey textured slate surface
Multiple pairs of hands with bluey-green pigment from persicaria tinctoria leaves on a brown surface
People sorting through a large pile of green Japanese indigo leaves.
Gardening plot with rows of persicaria and woad plants in a field
Close-up of a persicaria plant with green leaves and small white flowers in a field.
Collage of green leafy plants with color swatches below

Japanese Indigo Seeds
PERSICARIA TINCTORIA

Regular price €5,00 Save €-5,00
43 in stock

PERSICARIA TINCTORIA SEEDS

(Persicaria tinctoria / Japanese Indigo)
Dye Colour: Blue (Indigo) | Produced in Ireland

Persicaria tinctoria, commonly known as Japanese Indigo, is a fast-growing annual prized by natural dyers for its high indigo content and reliability in temperate climates. Its vibrant green leaves are the source of rich blue indigo pigment, suitable for fresh-leaf dyeing, pigment extraction, and traditional Sukumo vats.

A cornerstone plant for natural dye gardens, Persicaria produces clear, vibrant blues when grown well and harvested at the right moment. It is very frost sensitive and should be protected with horticultural fleece if late frosts occur after planting out.

Dye Fastness: Excellent (with proper indigo processes)


🌱 Basic Growing Information

  • Sowing period:
    Indoor sowing mid-March to mid-April
    Direct sow outdoors from mid-May, once frost risk has passed

  • Germination time: 7–14 days

  • Height: 60–90 cm (24–36 in)

  • Preferred location:
    Full sun to light shade; fertile, consistently moist but well-drained soil

  • Climate note:
    Frost and wind sensitive — sheltered planting improves growth and pigment yield


✂️ Harvesting Persicaria tinctoria

Harvest leaves when plants reach 40–50 cm, up to 2–4 times during the growing season, allowing fresh regrowth between cuts. For fresh-leaf dyeing or pigment extraction, leaves should be processed as soon as possible after harvesting to retain colour strength.


🌼 Variety & Trial Notes

This is a white-flowered variety that produced the highest pigment yield in our 2024 Persicaria variety trials, which compared seven different types grown in Ireland. It was also the earliest flowering variety, making it particularly suitable for outdoor seed saving in Ireland in most years.

(See the final product image for trial results — this variety is shown as Sample No. 5.)


📦 Additional Details

  • Open-pollinated & organically grown in Ireland

  • Germination rate: 85%

  • Irish seed licence: IE010713

  • Approx. 25 seeds per packet


Please note: Seeds and plants can only be shipped within Europe.

🌿 Join the Natural Dyers & Growers Academy to share growing experiences, learn indigo techniques, and connect with fellow growers.


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