Picture of Growing Blue
The allure of indigo has always fascinated me. I've purchased blue powder and dyed yarns in the past, but always wanted to do some batik fabrics. This was the year. And to actually grow the plants that will produce the color blue. Blue is elusive in the plant world, a few flowers like forget-me-nots or hydrangeas are blue, but you can not extract a blue dye from them. There are several plants that contain the chemical indican from which you can produce a blue dye. They include woad, dyer's knotweed,  Indigo tinctoria, and I. suifruticosa.  I planted dyer's knotweed (polygonum tinctorium), as it was the easiest to obtain seed, and also to grow in my area of the Midwest. 

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Step 1: Planting and growing

Picture of Planting and growing
I ordered seeds from an indigo project undertaken by Rowland Ricketts at Indiana University. I started the seeds indoors under florescent lights as they require a long growing season. It has definitely been that, this year, but one never knows. (We still have not had a frost the middle of October.) Because of a late wet and cold spring I did not plant them into the ground until the beginning of June. They grew well in my organic plot at the community garden. I perhaps planted them too close together, but they produced more than I needed for my first year of experimentation. 

Step 2: Harvesting the plants

Picture of Harvesting the plants
knotweed branches.jpg
withered leaves.jpg
The information I read said to pick them in the August or September, when the leaves are starting to show a blue tint from crushing or insect damage. I cut a few plants and let them wither to see what would happen. Yep...starting to look blue!
nah892 months ago

When you say to cover do you mean just covering leaves or to the top of the pot?

cookery (author)  nah892 months ago
The water should be deep enough to cover the leaves. You do not have to put a cover on the pot.
lauraabcd7 months ago
Qué lindo el proceso que hiciste , fantástico
cookery (author)  lauraabcd7 months ago
Thank you!
crazyg8 months ago
grow your own dye, impressive !
cookery (author)  crazyg8 months ago
Growing and using indigo was so exciting. Green leaves to blue dye. Just amazing. Give it a try!
LaffyDuck1879 months ago
I dye all my wool with lapis :)
cookery (author)  LaffyDuck1879 months ago
Where do you get it? How do you do it?
oh just a harmless minecraft reference. In minecraft, you dye wool blue by combining a lapis lazuli ore with a wool block
cookery (author)  LaffyDuck1879 months ago
oh...that's too easy...a click and it's done!
lazybird199 months ago
I think it would be cool to grow some but it's is easier to get my hand on some woad. It is an invasive species and is taking over some very big plots of land here in Utah.
cookery (author)  lazybird199 months ago
I grew some woad too. I did not have much luck with it. This dyer's knotweed seemed to have more indican in it. If it grows wild, definitely give it a try. I don't see it around here.
GemFOX9 months ago
Thank you SO much for sharing this. I have been dying for a natural dye for the cotton I grow on my patio here in the south. I can grow the indigo right next to my cotton, how cool. I have a small collection aizome fabrics from Japan and would love to make my own. Thanks and great 'ible. Your results are stunning and inspiring! Do you have any indigo seeds for sale?
cookery (author)  GemFOX9 months ago
How exciting to grow cotton! The beauty of indigo is that it works on all natural fibers and doesn't have to be boiled like other natural dyes. I'm hoping to use it on linen soon. I wish I had thought ahead enough to save more seed, but only have enough for my small plot. Maybe next year. Glad you enjoyed the 'ible!
GemFOX cookery9 months ago
Yeah I've been trying to find ways to dye my cotton balls before spinning, without mordant or commercial dyes. So I've been looking at turmeric, saffron, ochre, onion, and straight up iron oxide, all of which are in the yellow and orange tones and not the easiest to obtain. Growing indigo will make the pigment practically free and I love gardening so this is perfect. I can't wait to get my hands on some seed and try it. Thank you so much!
cookery (author)  GemFOX9 months ago
I grew a few other dye plants in my little plot this year also. The most rewarding were weld (a very clear yellow) and dyer's coreopsis (which produced a rich rust color with varying shades of peach in lesser proportions) I over-dyed the weld dyed wool with indigo and got an interesting green. So many possibilities! Today we have snow flakes, so my gardening days are over for a few months...
So cool how it changes colour as it oxidizes!

You might try cooking the leaves in a crock pot so you could keep it going all night (assuming longer simmering time = stronger dye, which might not be true.)
cookery (author)  jjdebenedictis9 months ago
A crock pot is a great idea--less watching the pot. You have to have a dedicated pot, as you don't want to mix food with craft ware. Will have to go to some yard sales and find one cheap. I don't think longer time simmering would produce more dye. There's only so much pigment in the leaves. I know I will do a lot more experimenting next summer! It was so much fun.
ljackson cookery9 months ago
If you go to your local grocery store and look with aluminium foil and wax paper they might have crock pot liners. We use them since our crock finish has deteriorated over the years. It would keep you from having to add another crock pot to your collection of kitchenware.
cookery (author)  ljackson9 months ago
Good idea...I'll check that out. Thanks!
rof9 months ago
Investigating my sources of seeds I find that the polygonum is now known as persicaria tinctoria. You'll get them here.

cookery (author)  rof9 months ago
Thanks so much! I love this international community!
1chelseA9 months ago
Very cool! Where can I get the seed for this at??
cookery (author)  1chelseA9 months ago
Send a request to Rowland at the Indiana University link and he will let you know when they are available in the spring.
Do you have an email or snailmail address for Mr. Rowland?
cookery (author)  keith152299 months ago
In the Indiana University link I gave in the article there is a contact: See other comments for a source of seed from Companion Plants. I have purchased seeds and plants from them in the past.
oookdg9 months ago
So incredibly cool! You did a beautiful job with the explanation and the photos. Inspiring. I will be looking for some seeds. And looking forward!
Cheese Queen9 months ago
Seed for dyer's knotweed is also available here>>
cookery (author) 9 months ago
I used polygonum tinctorium, dyer's knotweed, from Japan. I looked up Japanese knotweed, and see a big difference. Thanks for the clarification. I'll edit the text. Thanks!!!
what species of plant did are you using? The plants in your pictures do not match the plants that I know as japanese knotweed. (a very tall weed around here) and google image search didn't clarify it for me either.
This is so awesome - I've always wanted to try this. Now I'll have a much easier time, thanks to your instructions. :) I love your blog, too.
cookery (author)  supersoftdrink9 months ago
You are welcome. Thanks!!
PaganRaven9 months ago
Absolutely beautiful! And such patience! I would have been so antsy waiting on the plants to grow to then do the dying. Very well written too - I might give this a go come spring.
cookery (author)  PaganRaven9 months ago
Thanks! It was very exciting to see the colors change into blue.
audreyobscura9 months ago
Cool! Thanks for the share.
cookery (author)  audreyobscura9 months ago
You're welcome. It was a fun project.

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