I made four dyes this year: beet, purple cabbage, yellow onion skin, and tree bark. I fill the individual pots with cold water until covering the matter, then bring to a gentle simmer for an hour or so. Then I strain, add a tablespoon of vinegar per 8 oz, and that is it. I hoped to get green from my tree bark, but it was just a nice brown. One day I will achieve a real green. As always, my favorite dye is cabbage.