I have always enjoyed how the goldenrod grows and blooms alongside the purple asters – a beautiful combination of complimentary colors. Goldenrod (Solidago sp.) is a member of the aster family. There are many solidago species native to North America, and they can also be found in other parts of the world.
Is goldenrod a good source of dye? Yes, but with reservations.
Though it is not one of the “classical” dyes, and it’s lightfastness does not match that of weld, it was used as a locally available dye in North American and Europe. Dominique Cardon (Natural Dyes: Sources, Tradition, Technology, and Science) writes about goldenrod’s historical use, along with weld and Persian berries, to dye the yellow hats the Jews were required to wear in the south of France in the 13th century.
I’ve always read that goldenrod does NOT dry well for future use – so I never tried to dry it. I can accept the fact that some dyes deteriorate in the drying process. Black walnut hulls are a good example.
A couple years ago I was teaching a class here in Asheville, NC on dyes that could be sourced from the local food co-op. I used dried goldenrod plant material, as it is used medicinally. It resulted in very good color. So I began to wonder….. CAN A GOOD DYE BE OBTAINED FROM DRIED GOLDENROD?
It’s one thing to read a statement about a plant – it’s another thing to know and understand that statement. I had never tried to dry goldenrod. This year I finally got around to doing my own testing.
I gathered fresh goldenrod, and used that to dye aluminum mordanted wool, silk, and cotton. There are many yellow dyes in goldenrod and they may include quercitron, isoquercitron, kaempferol, astragalin, isorhamnetin. Since the dyes in goldenrod are primarily flavonols, a mordant is required.
I dried goldenrod from that same harvest. Plants were hung upside down in a dry space with plenty of air flow. Only the flowering heads were used as a source of dye. I was able to accurately determine the weight of the plant before and after drying. 300 grams of fresh goldenrod flowers resulted in 100 grams of dry flowers.
I dyed with fresh goldenrod at 300% w.o.f, while the dried was used at 100% w.o.f. Because I knew the weight before and after drying, I was confident that I was using the same amount of dye, whether it was fresh or dry plant material.
The results: The dyes seem not to have suffered from the drying process. Careful drying is likely a key element. So yes, I will dry some goldenrod and I will complete lightfastness tests on all three fibers. The goldenrod will not replace the weld that I grow and dry each year, Weld will always be my primary yellow dye as that has proven to be the best, and most lightfast yellow dye. But it is good to know a bit more about the dyes from plants available in my neighborhood.
Thus far I have used only the flower heads for dyeing. Maybe next year I’ll experiment with the stems and leaves from the entire plant.
The Art and The Science of Natural Dyes by Catharine Ellis and Joy Boutrup, available in late fall, is now available for pre-order.
Natural Dye: Experiments and Results 