Pokeberries are toxic but they make a beautiful dye. How toxic they are seems to not be clear. So inform yourself and decide. The berries were used as an ink in the 1800's. Some eat the new shoots in the spring. They do need to be cooked a few times to remove the toxins.
In general berries do not yield good long lasting dye color. I came across some info from Carol Leigh, here, and used them to the best of my ability. Then dyed up 5oz or so of roving.
I collected the pokeberries about 1.5 gallons worth maybe more maybe less. Tossed them in a bin and added a good glug of vinegar and enough water to cover them. Then crushed them a bit. This set overnight.
The next day I cooked the fiber in my crockpot with a few glugs of vinegar. I didn’t use acetic acid just lots of vinegar but I don’t have exact amounts, because I really wasn’t sure on the 56% acetic acid thing. Later I found that citric acid crystals can be used in place of it yet I’m still not convinced that’s true. Mainly I made sure I was using copious amounts of vinegar. Then I took out the fiber and let it cool for a bit.
I got the dye liquor ready by crushing the berries even more. I only used a strainer to remove the berries but wish I had used some cheese cloth as that would have collected the seeds. I had more dye liquor than I needed.
I added the dye liquor into the crockpot and another glug of vinegar. Then I added the fiber. Later I added some citric acid about 4oz to the dye bath. Let the fiber cook for about 30 more minutes after it reached 180 deg F.
Let it soak over night until cool. I rinsed it in the morning and still had lots of color left in the dye bath but the fiber was quite dark. Here are the lovely results!
I saved all the dye liquor I didn't use, 3 quart jars full. I may dye more.
Now I'm spinning it up.