25 Japanese Indigo Dye Plant seeds, Polygonum tinctorium, Persicaria tinctoria
AKA Indigo Dye Plant, Dyer's Knotweed and Chinese Indigo. Polygonum tinctorium, Persicaria tinctoria. Medicinal plant with a long history of use in Asia.
Once upon a time, all dyes were plant or mineral based. The Japanese indigo plant was highly valued for its bright blue color as a permanent dye used two millennia ago. Japanese strain of indigo preferred by many plant dyers.
A tender annual, indigo thrives in fertile soil and likes heat and humidity. Best started indoors 6–8 weeks before the last frost, transplanted out on 1 ft centers and kept moist. When the plants have grown 1–2' tall and the bruised leaves turn navy blue, they are ready for a first harvest. If you cut the stems several nodes up from the ground, they will re-sprout and you can harvest the re-growth, perhaps several times more.
The stems and the leaves are antidote, anti-inflammatory, antiphlogistic, antipyretic and depurative. Their use increases the phagocytosis of white blood cells and decreases the permeability of the capillaries. The indigo pigment in the leaves is used in the treatment of freckles, pimples, erysipelas, mumps, thrush, epidemic protitis, infantile convulsions and high febrile conditions of children. The leaves and fruits are used in Korea to help protect the liver and to treat burns and food poisoning caused by eating fish. The fruits are antidote and febrifuge. The plant is anti-inflammatory.
Photo shows blue dye as used still in Korea.