Rhubarb originated in Central Asia and still occupies a revered place in traditional Chinese medicine. Scientists around the world continue exploring various rhubarb species for their potential in treating ailments as diverse as dermatitis, pancreatic cancer, and diabetes. (Note: The Rheum genus contains at least 60 species and many hybrids; the succulent species that we bake into pies differs from the medicinal rhubarbs, which are generally considered inedible.)
Because of its high concentration of oxalic acid (the compound that makes the leaves and roots toxic to eat), rhubarb has also found use as an agent for cleaning metal, tanning leather, and controlling insects.
One of the more intriguing uses for the root (actually a rhizome) of this ancient plant: as a lightening agent for blond or light brown hair. The oxalic acid serves as a fixative, so a rhubarb rinse will last much longer than most herbal rinses.
Rhubarb Rinse Recipe
Brave enough to give it a try? Purchase some dried, chopped rhubarb root in a local health food store; if you have rhubarb growing in your garden, dig up a chunk of the rhizome, scrub it well, and dice it.
Herbalists say that the strongest dye comes from the medicinal rhubarb species, but the roots of homegrown pie rhubarb will work, too, with a milder effect. Keep all rhubarb root away from children and pets.
Simmer 3 to 4 tablespoons of dried rhubarb root or half a cup of fresh, chopped root in a quart of water for 20 minutes in a covered stainless-steel pot. (Don’t breathe the steam.) Let the decoction steep overnight, then strain in the morning.
Test the liquid dye on a strand of hair first to see if you like the color. If you do, wash your hair as usual, then pour the rhubarb dye through it, catching the liquid in the pan and repeating two or three times. Air dry without further rinsing.
Did I try it myself? Yes! It gave a soft, golden glow to my tired gray-white locks.
Margaret Boyles is a longtime contributor to The Old Farmer’s Almanac. She wrote for UNH Cooperative Extension, managed NH Outside, and contributes to various media covering environmental and human health issues. Read More from Margaret Boyles