Known variously as Japanese or Chinese Indigo, or Dyer's Knotweed,this is a tender annual used for centuries in the East to produce a blue dye with the same chemistry as that in Indigo, but it is easier to grow and to use. Seed is however difficult to come by and said to be not viable for very long. The small amount of seed we have at present is part of a batch from which plants were successfully germinated earlier this year. We also have plants available in spring. (see our Natural Dye Plants section to buy plants, and Books section for Rita Buchanan's book that describes its cultivation and dye use.)
It needs warm, humid conditions to germinate and to grow. Best sown in a heated propagator and only planted outside after the begining of June in the UK.
It is NOT the same plant as the infamous "Japanese Knotweed", though it is in the same family! It cannot become invasive as it dies completely in winter. It has pretty spikes of pink flowers which are good in the border and attract insects.
seed currently available.