Two pictures, by request.
Here are the blankets that sit at the foot of our bed, - handwoven many years ago (thirty five or forty) and woven from pure wool. The wool was dyed with Rabbit Brush and Golden Rod,plants that naturally produce yellow, but with the use of mordants can achieve lovely greens and tans and browns.
Here are the two plants that were used to dye these old blankets. Both the Rabbit Brush and the Goldenrod grow profusely in this valley, and what fun I had collecting them when I was young and agile.
Goldenrod – All goldenrod will produce a beautiful bright yellow, but it is necessary to use a mordant to make the colour 'take'. The safest and easiest mordant to use is alum and tartaric acid (cream of tartar purchased from the grocery store). The alum must be purchased from a craft store, - drug store alum won't do the trick.
The yellow in the border of the blanket on the left was dyed with goldenrod, and I wish I could remember for sure what I used to obtain the brown but it was probably walnut hulls. When I had this blanket on the loom I was doing quite a bit of demonstrating and teaching, and the blanket grew longer and longer. When I eventually cut it from the loom it was (and still is) long enough to make two cot sized blankets. It is lovely and warm.
Rabbit brush also yields golden dyes. Climate, seasons and plant maturity factor into the colour any given dye plant will produce and this applies to Rabbit Brush particularly. This randomness in color is part of the excitement in dyeing. In this semi-desert country the amount of rainfall, or lack of it, will affect the depth of colour.
Mordants also affect dye colors. A mordant is usually a mineral salt such as alum, tin or copper which is added to a dye bath to assist the bonding between dye molecules and the protein fibers of sheep's wool'.
The blanket on the right was woven exclusively with wool dyed from Rabbit Brush and various mordants, - the addition of copper produces green, chrome and tin both brighten (chrome is toxic and requires the use of rubber gloves) and iron saddens the colours.
If you are interested in dyeing wool with natural plants here is a good place to start.
And Barb, here is a picture of the Sweet Autumn Clematis that grew in our old garden - it looks so delicate, but was strong and hardy and bloomed right until frost - even until November.