I seeded Japanese Indigo (Polygonum Tinctorium) seeds in January and it took exactly two weeks for them to germinate inside the greenhouse. If I had pre-soaked the seeds it could have speed up the germination process. After six weeks in the greenhouse the roots were mature enough to be transplanted.

Isatis tinctoria

Note: The blue or indigo dye is obtained from the leaves of Indigofera tinctoria.

Historically, indigo was a natural dye extracted from the leaves of some plants of the Indigofera genus, in particular Indigofera tinctoria; dye-bearing Indigofera plants were commonly grown and used throughout the world, in Asia in particular, as an important crop, with the production of indigo dyestuff economically …

Seed your indigo indoors in trays or cells as you prefer / have available ( even plastic food trays). Use good fine seeding soil for best results, cover seed lightly with soil, water and place in a warm and sunny location. Seeds will germinate within 2 -3 weeks.

It prefers fertile, well-drained soil, moderate moisture, and full sun, except in very hot climates, where it appreciates some afternoon shade. A medium shrub, the indigo plant will grow to 2 to 3 feet (61-91.5 cm.) in height and spread. In the summer, it produces attractive pink or purple flowers.

Indigo is edible and can be consumed as a tea. Not only are the leaves and stems used, but also the root, flower and seed depending on the season.

Indigo is an ancient dye, sold as a striking and bold blue crystalline powder. It has been used in many civilizations and was popular in Mayan, Egyptian, Japanese and Indian cultures. Its common use is in creating the popular Shibori and tie dye fabrics as well as denim.

As adjectives the difference between indigo and lavender is that indigo is having a deep blue colour while lavender is having a pale purple colour.

Indigo dye is a greenish dark blue color, obtained from either the leaves of the tropical Indigo plant (Indigofera), or from woad (Isatis tinctoria), or the Chinese indigo (Persicaria tinctoria). Many societies make use of the Indigofera plant for producing different shades of blue.

Periwinkle

The main difference between Blue and Indigo is that the Blue is a color; additive and subtractive (RYB) primary color; visible between purple and green and Indigo is a deep and bright shade of blue. It lies between violet and green on the spectrum of visible light.

Indigo color is a unique shade, which is quite distinguishable on the color palette. It combines both purple and blue. What’s interesting, it is used for many different purposes. Indigo matches many other colors.

Frequency: Indigo is defined as a deep bluish purple color or dye. An example of indigo is a dark bluish purple iris flower.

Today, the color “indigo” refers to a blue-purple color that many people can’t actually distinguish from blue or purple. But many believe that what Newton called “blue” was closer to the modern “aqua,” a mix between blue and green, and that his “indigo” was what we’d call “blue” today.

Indigo, being a color directly between blue and violet, is so close to both colors that it’s often never recognized as indigo. Theories that support Newton consider the wavelength of indigo. On the visible color spectrum, each of the seven colors has a specific range of wavelengths.