Wild Colours natural dyes home

Change text size?

close menu

Wild Colours 


Handmade cards with natural dyes

Handmade cards

Wild Fibres - natural fibres for felting, spinning & dyeing!

Wild Fibres - natural fibres for felting, spinning & dyeing

Wild Paper handmade paper for printing, artists & gift wrap

Wild Paper - handmade paper for computer printing, artists & wrapping presents

Japanese Indigo

        Wild Colours - Exciting colours from Natural Dyes


Wild Colours natural dyes > blue dye plants > japanese indigo

Japanese Indigo (Persicaria tinctorium)

(was Polygonum tinctorium)

Japanese indigo in flower - a blue natural dye plantJapanese Indigo, also known as Dyer’s Knotweed, is an annual, growing to 75 cm tall. It is a member of the family Polygonaceae and it is related to rhubarb and dock.

The leaves are soft and dark green, and the plant has swollen jointed stem nodes, which are somewhat hairy.

The small white or pink flowers are hermaphrodite (have both male and female organs) and are pollinated by insects. Some greenhouse plants start to flower in late August but others only start to flower in early October.

1. Cultivating Japanese Indigo

2. Harvesting Japanese Indigo

3. Extracting Indigo Pigment (opens new page)

4. Dyeing with Japanese Indigo (opens new page)

Buy Japanese Indigo seeds

Japanese Indigo plants in greenhouse - blue natural dye plant
Unlike the pest species Japanese Knotweed, to which it is related, Japanese Indigo is frost tender and needs protection from cold weather.

And watch out for caterpillars eating the leaves of greenhouse plants in late September. I have not had any success in over-wintering Japanese indigo as all my plants tend to succumb to greenfly.

1. Cultivating Japanese Indigo
Fresh seed is needed to grow Japanese Indigo and seed over two years old is unlikely to germinate. Sow your seeds indoors in early May, about two to three weeks before the date of the last frost in your region.

Plant the seeds in a tray of compost, but do not cover the seeds with soil. Watering the seeds with the rose of a watering can will cover them up enough. The seeds usually germinate quickly and the plants also grow relatively fast. Be sure to protect your plants from frost though.young Japanese Indigo plants in pot

Japanese Indigo likes a rich soil and plenty of water. When the plants are big enough, I plant them in 5 litre pots and keep them in a greenhouse with the door open. I plant some seedlings outside one week after the last frost and Japanese Indigo should thrive outside in warmer years and in more sheltered positions in the UK.

You can increase the number of plants by bending branches and tucking them into the soil.

Back to Top

2. Harvesting Japanese Indigo
You can  harvest the leaves as soon as the plant is large enough and before flowering starts. One of my pot plants produced about 250g of leaves, and one of my outdoor plants produced over 1 kg.

harvesting Japanese Indigo leaves for dyeRinse the leaves in cold water and drain them.

Feed and water the plant well after each cutting and it should then produce another harvest in about four to five weeks.

And then (next page);

3. Extracting Japanese Indigo pigment
Details of Japanese indigo extraction.

4. Dyeing with Japanese Indigo

Top of page


How to contact us:-
Wild Colours natural dyes, Studio 319, Scott House, The Custard Factory, Gibb St, Birmingham B9 4DT, UK

Contact Teresinha for enquiries
Tel:    +44 (0)7979 770865
email: info@wildcolours.co.uk

[search] [Contact us] [Ordering] [safety] [Terms] [International] [About us] [Links]

UK Shipping 4.95p on orders up to 100 & free over 100 in UK
[shipping 2.95 on very small orders up to 2.95 in value]

Delivery to Europe + rest of World click here
Overseas orders sent by Tracked Airmail

Special & Next Day Delivery

Updated on 22 April 2024
Website & photos by Mike Roberts ©2006-24 Wild Colours natural dyes


Site Search Site Search