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.

IRISH WOAD SEEDS – Isatis tinctoria

(Traditional Indigo Dye Plant)
Dye Colour: Blue | Produced in: Ireland

Irish Woad (Isatis tinctoria) is a historic European indigo plant, cultivated for centuries as a source of blue dye. Grown to organic standards in Ireland, this biennial plant produces lush, succulent leaves in its first year, followed in its second year by tall flowering stems and foamy clusters of bright yellow flowers.

Valued for both its dye quality and garden presence, Woad is a cornerstone plant for dyers wishing to develop reliable, home-grown blue pigment.

Colour fastness: Medium to Good (depending on dye method)

🌱 Basic Growing Information

Sowing period
February to March (in trays)

Germination time
7–21 days at 15–18 °C (59–64 °F)

Height
Up to 1 m (3 ft)

Preferred location
Full sun with well-drained soil

✂️ Harvesting for Dye & Seed

First year
Harvest leaves from July to September for dyeing

Second year
Allow plants to flower and collect seed. Leaves no longer produce dye at this stage.

📦 Additional Details

Grown to organic standards in Ireland for conservation purposes
Germination rate: 85%
Approx. 100+ seeds per packet
Irish seed licence: IE010713

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

Join The Natural Dyers & Growers Academy to share your experiences, join courses and get support from fellow growers and dyers.

WOAD ‘BIRMINGHAM’ SEEDS – Isatis tinctoria

(Pastel Blue Indigo Variety)
Dye Colour: Pastel Blue | Produced in: Ireland

Woad ‘Birmingham’ is a distinctive variant of Isatis tinctoria, originally developed in Canada and now grown and selected in Ireland. Recognised for its crinkled, waxy foliage and reliable first-year performance, this variety produces soft, refined pastel-blue dye when harvested at the right stage.

In its second year, plants develop tall stems reaching around 1 m in height, followed by foamy clusters of bright yellow flowers and seed production. As with other woad varieties, useful dye is produced primarily in the first growing season.

This variety is particularly suited to dyers exploring subtle tonal ranges, eco printing, and varietal comparisons within indigo plants.

Colour fastness: Medium to Good (depending on dye method)

🌱 Basic Growing Information

Sowing period
Late February to March (in trays)

Germination time
7–21 days at 15–18 °C (59–64 °F)

Height
Up to 1 m (3 ft)

Preferred location
Full sun with well-drained soil

✂️ Harvesting for Dye & Seed

First year
Harvest leaves from early June onwards for dyeing

Second year
Allow plants to flower and collect seed. Leaves no longer produce dye at this stage.

📦 Additional Details

Grown in Ireland
Germination rate: 85%
Approx. 50 seeds per packet
Irish seed licence: IE010713

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

Join The Natural Dyers & Growers Academy to share your experiences and get support from fellow growers.

WOAD ‘TEWKESBURY’ SEEDS – Isatis tinctoria

(Traditional Indigo Dye Plant)
Dye Colour: Strong Blue
Produced in: Ireland

Woad ‘Tewkesbury’ is a renowned variety of Isatis tinctoria, long valued for producing some of the strongest and most reliable blue dyes available from European-grown indigo plants. Originally identified near Tewkesbury in the UK, this variety has become a favourite among natural dyers for its consistency and pigment strength.

In its first year, Woad produces lush, succulent leaves that are harvested for fresh-leaf dyeing, pigment extraction, and traditional indigo processes. In its second year, the plant flowers and produces seed, and the leaves no longer yield usable dye.

With stems reaching around 1 m in height and foamy clusters of bright yellow flowers in its second year, Woad is both a productive dye plant and an attractive structural feature in the garden.

Colour fastness: Medium to Good (depending on dye method)

🌱 Basic Growing Information

Sowing period
Late February to early April (in trays)

Germination time
7–21 days at 15–18 °C (59–64 °F)

Height
Up to 1 m (3 ft)

Preferred location
Full sun with well-drained soil

✂️ Harvesting for Dye & Seed

First year
Harvest leaves from early June onwards for dyeing

Second year
Allow plants to flower and collect seed. Leaves no longer produce dye at this stage.

📦 Additional Details

Grown to organic standards (not yet certified)
Germination rate: 85%
Approx. 50+ seeds per packet
Irish seed licence: IE010713

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

Join The Natural Dyers & Growers Academy to share your experiences, join courses and get support from fellow growers and dyers.

ANNUAL WELD SEEDS – Reseda luteola

(Traditional Yellow Dye Plant)
Dye Colour: Yellow
Produced in: Ireland

Reseda luteola, commonly known as Weld, is one of the most important historic yellow dye plants, valued for its exceptional clarity and lightfastness. Its tall, slender flower spikes and narrow leaves produce strong, clean yellows that form the foundation for greens and oranges when overdyed with indigo or madder.

Weld is normally a biennial, flowering in its second year. However, this particular variety shows the unusual and reliable trait of flowering in its first year under Irish growing conditions. This makes it especially valuable for dyers seeking faster access to usable dye material, while still maintaining good colour quality.

A cornerstone plant for professional natural dye practice, Weld remains central to gardens focused on consistent, high-grade colour production.

Dye fastness: Excellent (one of the most lightfast natural yellows)

🌱 Basic Growing Information

Sowing period
Mid-March to mid-April indoors
Direct sow from mid-May

Germination time
8–14 days

Height
100–150 cm (40–60 in)

Preferred location
Full sun with well-drained soil
Tolerant of poor or dry ground

✂️ Harvesting for Dye

Harvest the whole plant when approximately half of the flower spikes are in bloom, which is when dye content is at its highest. Cut at the base and use fresh, or dry thoroughly for later use.

Leaves, stems, and flower spikes are all suitable for dyeing and produce strong, clear yellows.

Flowers and plant material may be used fresh or dried for dyeing and eco printing.

🌼 About This Variety

This variety was identified during our 2024 Weld variety trials. While several trial varieties flowered in their first year, none did so as consistently as this one.

As it is the flowering plant that is used for dyeing, this trait offers a significant practical advantage by saving a full growing season. However, dye content testing showed that this variety produces slightly paler colour than our traditional biennial Weld (see Sample No. 5 in the final product image).

This presents an important choice for growers and dyers:

• A usable crop in one year with slightly lighter colour
• Or a brighter crop requiring two full growing seasons

📦 Additional Details

Open-pollinated & organically grown in Ireland
Germination rate: 68%
Approx. 75 seeds per packet
Irish seed licence: IE010713

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

Join The Natural Dyers & Growers Academy to share your experiences and get support from fellow growers.