For yellow dye, plant onions and flowers now and harvest them in spring. Or collect them from other sources (ask for leftover onion skins at grocery stores). Buy wool at knitting shops.
If using onions, you'll need:
- Mild dishwashing liquid (such as Dawn)
- 2 ounces unspun wool
- 6 ounces yellow onion skins
- 1 tablespoon alum (aluminum potassium sulfate)
- 1 tablespoon salt
- 2 tablespoons white vinegar
- Rubber gloves
1. Wash wool. Soak for 20 minutes in a standard-size plastic dishpan filled halfway with warm water and about 10 drops dishwashing liquid. Gently push wool into water with a spoon, but don't agitate. Rinse in warm water and hang to drain off excess water.
2. Simmer (this step can be done the night before). Fill slow-cooker halfway with cool water. Add onion skins, alum, salt, and vinegar and stir. Add wool and enough additional water to cover. Gently agitate the wool. Simmer for 1 hour. Shut off and let cool.
3. Hang to dry. Wearing gloves, remove wool from slow-cooker and hang to dry on a clothesline (install in an area where dripping dye won't stain anything). Pick off onion skins when dry.
If using flowers:
- Collect mature blossoms of coreopsis, marigolds, and/or yellow zinnias. Do not collect leaves.
- Pull petals from flower heads and place in a pouch made of four layers of cheesecloth; tie closed with string. Use 1½ ounces of petals per 2 ounces of wool.
- Follow the instructions above, omitting onions and substituting 1 teaspoon of cream of tartar for the vinegar and salt.