Persicaria - Japanese Indigo (Persicaria Tinctoria) Indigo Dyers Knotweed Plant Non GMO - Flower

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Persicaria - Japanese Indigo (Persicaria Tinctoria) Perennial Dyers Plant Non GMO - Flower

Perennial - Deciduous

Height 2 to 4 ft

Persicaria, commonly known as Chinese indigo, Japanese indigo and dyer's knotweed, is a species of flowering plant in the buckwheat family. This is a captivating hardy perennial plant renowned for its vibrant blue dye colour producing leaves. It boasts a rich history of use in traditional textile dyeing practices, making it a fascinating addition to any garden.

Persicaria tinctoria (or Polygonum tinctoria) is a frost tender member of the knotweed family and originates from China and Vietnam - hence it likes to grow in warm moist climates, and often as a waterside plant. Japanese Indigo will grow from seed to flower in one season. 

Japanese Indigo has lush, lance-shaped leaves that exhibit a striking green hue during the growing season, and as it matures, its leaves transition to a deep blue-green colour, which is indicative of their dye-producing potential.

Plants typically reaches a height of 2 to 4 feet, and form a bushy and attractive feature in any garden. Staking may be necessary to maintain an upright and well-organized appearance. Simply enjoy its lush green foliage or why not create your own natural dyes for textile projects! 

  • Full sun exposure for optimal growth and vibrant leaf coloration.
  • Well-draining soil with good organic content. A slightly acidic to neutral pH level is ideal for this plant.
  • Start seeds indoors 6 to 8 weeks before the last frost date.
  • Plant seeds approximately 1/4 inch deep in warm soil.
  • Transplant seedlings into 1 in cells or 2 in pots when they reach the 1 to 2 leaf stage.
  • Note: if the seedlings become leggy due to insufficient light, burying more of the stem during transplantation is permissible, as it will develop roots along the buried portion without hampering growth.
  • Germination: typically within 7 to 14 days, depending on conditions.
  • Hardening Off: Before transplanting outdoors, harden off the plants for 4 to 5 days after the risk of frost has passed to acclimate them to outdoor conditions.
  • Spacing: 24 to 36 in apart.
  • Matures: 50 to 55 days, at which point you can begin harvesting the leaves for dye extraction.
  • Harvesting Seeds: when the flowers go brown they can be cut and hung up or laid out to dry - some of the seed will fall out - the remainder can then be rubbed out. Separating the seeds from the chaff: once you have removed the seeds and dried flower material from the stalks, place the whole lot in a tray and shake from side to side and all of the heavy seeds will settle to the bottom - if you are careful you can blow lightly on the pile of chaff from the top and remove more chaff. Some of the seed will retain an outer layer of brown chaff bound to the seed; this does not impair germination. Store in a cool dry place until use.
  • Seed Count: 10