Dyeing Wool With Cosmos Flowers
Summer 1999: Rita Buchanan's book "A Dyer's Garden" promises a "Koolaid" orange from cosmos flowers on wool, so I had to try that. Yellow is a common natural dye color in North America, but orange is more rare. We grew Bright Lights, a yellow and rust commercial mix of the annual cosmos. Buchanan says the pink mixes aren't suitable for dye, being actually a different species. The yellow-toned Cosmos sulphureus varieties, however, are bright and easy to grow by seeding directly in the border or rows. Their leaves are lacy, as you can see from the sample in the picture. They are tall flowers, growing to about four feet.
We harvested the cosmos flowers frequently, two to three times a week, and simply froze them in a plastic five-gallon wastebasket liner bag as we picked them, thus collecting a lot over time. Cosmos produces many flowers all summer, and seeds are also easy to collect. Bees like to sleep in these flowers in the evening, so I learned not to pick at dusk.
I used about half of one of my frozen bags for 1 1/2 pounds of wool. The process is to simmer the flowers for about an hour in a kettle of water until they are bleached out and the dye is in the water. Then strain and dye the white wool for half an hour to an hour or so, simmering.
The mordant is the important thing with cosmos --- tin-mordanted wool yields the Koolaid orange, the light wool on the right in the picture, and it is a lovely color. It goes very well with light natural gray wool, for a two-color sweater. I used tin right in the dye bath rather than pre-mordanting. If I were concerned about the dye bath not exhausting and wanting to reuse it, I would have pre-mordanted the wool so as not to contaminate the dye bath.
The second, darker color on the left in the picture was made with a new batch of cosmos flowers, using a simple alum mordant. Buchanan suggests that tin not be used with the rust dyeing, because cosmos rust requires a high pH and that may damage the wool if tin is present. At the end of the dyeing, baking soda or ammonia is added. I ended up using both, and a fair bit more than the teaspoon Buchanan suggested, until I got a good color shift to rust. I was doing a lot more wool than her 4 oz. sample lots, however, probably 1 1/2 pounds. No damage to the wool resulted in my dye lot from the high pH.
The rust was very clear and pleasant from cosmos, a clearer rust than some dyestuffs produce. The Koolaid orange is indeed as nice as advertised. The ease of growing these flowers and collecting and using them, as well as the fine color, makes this a good choice for natural dyeing.
