How do you know if a plant might make a good dye? Rub it between your fingers and see if it stains. If it does give it a try!
To help the dye “bite” the yarn or fabric you need to use a mordant. Pickling alum is one I like to use; easy to find and non-toxic. Different mordants will give various shades so try a few!
Use the least processed, non-machine washable wool you can find. If it’s been treated it won’t take dye well.
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