Bindweed and I have finally come to terms. We have a long history together and our issues seem to be working out for the greatest good for all. Plus I've discovered that bindweed really has a heart of gold.
After cutting a half pound of bindweed, Convolvulus arvensis, vines, I covered them with water in an aluminum pot and simmered it for about an hour. Then I let it cool down and sit overnight.
The next day, I removed the plant material, added alum to the dye-bath, and simmered it for 15 minutes. Presoaked pieces of white or natural wool, silks and linen were added and simmered another hour or so.
That evening, I squeezed out the cloth for air-drying and ironing. Wool and silk took the color beautifully -- linen, the least. I guess I forgot to put cotton in. These are wrapped with a 36" flowering vine and there's plenty more where this came from.
I also tasted some while it was simmering as the whole house smelled like a spinach cannery.
Like I said, we're working things out.