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 for its high indigo content and reliability in the dye garden. Its green leaves are the source of rich blue indigo pigment, suitable for fresh-leaf dyeing, pigment extraction, and Sukumo vats. A cornerstone plant for natural dyers, it produces clear, vibrant blues when grown and harvested at the right moment. Persicaria is very frost sensitive and must be protected with horticultural fleece if late frost occurs after planting out.
Dye Fastness: Excellent (with proper indigo processes)
Basic Growing Information
🌱 Sowing Period: Mid-March to Mid-April indoors, direct sow Mid-May
⏳ Germination Time: 7 – 14 days
🌿 Height: 60 – 90 cm (24 – 36 in)
☀️ Preferred Garden Location: Full sun to light shade; fertile, consistently moist but well-drained soil
Additional Details
- Open-pollinated & organically grown in Ireland
- Germination rate: 85%
- License number: IE010713
- Approx. 25 seeds per packet
Harvesting Persicaria tinctoria
Harvest leaves when plants are 40-50cm tall 2–3 times during the growing season, allowing fresh regrowth between harvests. For fresh-leaf dyeing or pigment extraction, process leaves as soon as possible after cutting to retain colour strength.
This is a white flowered variety which gave the most pigment from the 7 varieties we trialed in our 2024 variety trials (read more about our trials here). It was also the earliest flowering variety, which makes it viable for seed saving in Ireland outdoors in most years. See the last product image here, where it is sample number 5 in our trial results.
NOTE: Seeds and plants can only be shipped within Europe.
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