Japanese (Dyer's) Indigo
Polygonum tinctorium. Tropical turquoise colour can be obtained by using only fresh leaves and ice water. Through a more complex fermentation process varying shades of indigo blue are released. (numerous websites have recipes for both types of dyeing) Start the seed indoors six weeks before setting outside in May after all danger of frost in a sunny location. It is very hardy until the first frost and likes to sprawl, space 1 – 2 feet apart. Leaves are ready to harvest when the first flower heads appear.